CLN: ASV Gil benchmark
- Adding missing `setup` import to `attrs_caching.py`

- Now lint benchmark files that start with g and h

- Utilized `params` for `gil.py` benchmarks, flake8 and remove start imports

```
asv dev -b ^gil
· Discovering benchmarks
· Running 15 total benchmarks (1 commits * 1 environments * 15 benchmarks)
[  0.00%] ·· Building for existing-py_home_matt_anaconda_envs_pandas_dev_bin_python
[  0.00%] ·· Benchmarking existing-py_home_matt_anaconda_envs_pandas_dev_bin_python
[  6.67%] ··· Running gil.ParallelDatetimeFields.time_datetime_field_day                                                   211ms
[ 13.33%] ··· Running gil.ParallelDatetimeFields.time_datetime_field_daysinmonth                                           224ms
[ 20.00%] ··· Running gil.ParallelDatetimeFields.time_datetime_field_normalize                                             324ms
[ 26.67%] ··· Running gil.ParallelDatetimeFields.time_datetime_field_year                                                  201ms
[ 33.33%] ··· Running gil.ParallelDatetimeFields.time_datetime_to_period                                                   258ms
[ 40.00%] ··· Running gil.ParallelDatetimeFields.time_period_to_datetime                                                   325ms
[ 46.67%] ··· Running gil.ParallelFactorize.time_loop                                                                         ok
[ 46.67%] ···· 
               ========= ========
                threads          
               --------- --------
                   2      76.9ms 
                   4      156ms  
                   8      314ms  
               ========= ========

[ 53.33%] ··· Running gil.ParallelFactorize.time_parallel                                                                     ok
[ 53.33%] ···· 
               ========= ========
                threads          
               --------- --------
                   2      95.9ms 
                   4      209ms  
                   8      474ms  
               ========= ========

[ 60.00%] ··· Running gil.ParallelGroupbyMethods.time_loop                                                                    ok
[ 60.00%] ···· 
               ========= ======== ======== ======== ======== ======== ======== ======== =======
               --                                        method                                
               --------- ----------------------------------------------------------------------
                threads   count     last     max      mean     min      prod     sum      var  
               ========= ======== ======== ======== ======== ======== ======== ======== =======
                   2      92.6ms   85.2ms   79.0ms   82.7ms   82.3ms   82.0ms   82.2ms   106ms 
                   4      187ms    163ms    158ms    164ms    156ms    165ms    160ms    207ms 
                   8      452ms    406ms    396ms    410ms    398ms    405ms    401ms    493ms 
               ========= ======== ======== ======== ======== ======== ======== ======== =======

[ 66.67%] ··· Running gil.ParallelGroupbyMethods.time_parallel                                                                ok
[ 66.67%] ···· 
               ========= ======= ======= ======= ======== ======= ======= ======= =======
               --                                     method                             
               --------- ----------------------------------------------------------------
                threads   count    last    max     mean     min     prod    sum     var  
               ========= ======= ======= ======= ======== ======= ======= ======= =======
                   2      150ms   104ms   105ms   83.9ms   104ms   103ms   103ms   111ms 
                   4      305ms   235ms   227ms   227ms    227ms   231ms   219ms   271ms 
                   8      740ms   466ms   481ms   504ms    493ms   515ms   484ms   709ms 
               ========= ======= ======= ======= ======== ======= ======= ======= =======

[ 73.33%] ··· Running gil.ParallelGroups.time_get_groups                                                                      ok
[ 73.33%] ···· 
               ========= =======
                threads         
               --------- -------
                   2      1.41s 
                   4      2.94s 
                   8      5.76s 
               ========= =======

[ 80.00%] ··· Running gil.ParallelKth.time_kth_smallest                                                                    291ms
[ 86.67%] ··· Running gil.ParallelReadCSV.time_read_csv                                                                       ok
[ 86.67%] ···· 
               ========== ========
                 dtype            
               ---------- --------
                 float     554ms  
                 object    24.4ms 
                datetime   561ms  
               ========== ========

[ 93.33%] ··· Running gil.ParallelRolling.time_rolling                                                                        ok
[ 93.33%] ···· 
               ================ ========
                    method              
               ---------------- --------
                rolling_median   239ms  
                 rolling_mean    24.7ms 
                 rolling_min     27.3ms 
                 rolling_max     29.1ms 
                 rolling_var     23.7ms 
                 rolling_skew    31.3ms 
                 rolling_kurt    29.7ms 
                 rolling_std     30.0ms 
               ================ ========

[ 93.33%] ····· 
                
                For parameters: 'rolling_median'
                /home/matt/Projects/pandas-mroeschke/asv_bench/benchmarks/gil.py:194: FutureWarning: pd.rolling_median is deprecated for ndarrays and will be removed in a future version
                  rolling[method](arr, win)
                
                For parameters: 'rolling_mean'
                /home/matt/Projects/pandas-mroeschke/asv_bench/benchmarks/gil.py:194: FutureWarning: pd.rolling_mean is deprecated for ndarrays and will be removed in a future version
                  rolling[method](arr, win)
                
                For parameters: 'rolling_min'
                /home/matt/Projects/pandas-mroeschke/asv_bench/benchmarks/gil.py:194: FutureWarning: pd.rolling_min is deprecated for ndarrays and will be removed in a future version
                  rolling[method](arr, win)
                
                For parameters: 'rolling_max'
                /home/matt/Projects/pandas-mroeschke/asv_bench/benchmarks/gil.py:194: FutureWarning: pd.rolling_max is deprecated for ndarrays and will be removed in a future version
                  rolling[method](arr, win)
                
                For parameters: 'rolling_var'
                /home/matt/Projects/pandas-mroeschke/asv_bench/benchmarks/gil.py:194: FutureWarning: pd.rolling_var is deprecated for ndarrays and will be removed in a future version
                  rolling[method](arr, win)
                
                For parameters: 'rolling_skew'
                /home/matt/Projects/pandas-mroeschke/asv_bench/benchmarks/gil.py:194: FutureWarning: pd.rolling_skew is deprecated for ndarrays and will be removed in a future version
                  rolling[method](arr, win)
                
                For parameters: 'rolling_kurt'
                /home/matt/Projects/pandas-mroeschke/asv_bench/benchmarks/gil.py:194: FutureWarning: pd.rolling_kurt is deprecated for ndarrays and will be removed in a future version
                  rolling[method](arr, win)
                
                For parameters: 'rolling_std'
                /home/matt/Projects/pandas-mroeschke/asv_bench/benchmarks/gil.py:194: FutureWarning: pd.rolling_std is deprecated for ndarrays and will be removed in a future version
                  rolling[method](arr, win)

[100.00%] ··· Running gil.ParallelTake1D.time_take1d                                                                          ok
[100.00%] ···· 
               ========= ========
                 dtype           
               --------- --------
                 int64    24.3ms 
                float64   8.17ms 
               ========= ========
```
