CLN: ASV reshape
Flake8'd and simplified setups where available.

```
$ asv dev -b ^reshape
· Discovering benchmarks
· Running 9 total benchmarks (1 commits * 1 environments * 9 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
[ 11.11%] ··· Running reshape.Melt.time_melt_dataframe                   7.27ms
[ 22.22%] ··· Running reshape.Pivot.time_reshape_pivot_time_series        441ms
[ 33.33%] ··· Running reshape.PivotTable.time_pivot_table                46.0ms
[ 44.44%] ··· Running reshape.SimpleReshape.time_stack                   6.73ms
[ 55.56%] ··· Running reshape.SimpleReshape.time_unstack                 6.05ms
[ 66.67%] ··· Running reshape.SparseIndex.time_unstack                   2.76ms
[ 77.78%] ··· Running reshape.Unstack.time_full_product                   254ms
[ 88.89%] ··· Running reshape.Unstack.time_without_last_row               477ms
[100.00%] ··· Running reshape.WideToLong.time_wide_to_long_big            378ms
```