Cloning fork on Windows fails due to asv_bench/asv.conf.json
I just forked the pandas-dev/pandas repo and tried to clone it on my Windows [Version 6.1.7601] box.

```
Z:\software>git clone https://github.com/Michael-E-Rose/pandas.git
Cloning into 'pandas'...
remote: Counting objects: 152309, done.
remote: Compressing objects: 100% (8/8), done.
remote: Total 152309 (delta 6), reused 0 (delta 0), pack-reused 152301
Receiving objects: 100% (152309/152309), 122.89 MiB | 1.68 MiB/s, done.
Resolving deltas: 100% (125964/125964), done.
error: unable to create file asv_bench/asv.conf.json: No such file or directory
fatal: cannot create directory at 'asv_bench': No such file or directory
warning: Clone succeeded, but checkout failed.
You can inspect what was checked out with 'git status'
and retry the checkout with 'git checkout -f HEAD'
```
First of all, upon (seeming) completion, the network drive Z disconnects.  Something along the process triggers that disconnect. After redownload, I tried `git status`, which results in a long list of green files marked deleted.  `git checkout -f HEAD` results in 

Z:\software\pandas>git checkout -f HEAD
fatal: Unable to create 'Z:/software/pandas/.git/index.lock': File exists.

Another git process seems to be running in this repository, e.g.
an editor opened by 'git commit'. Please make sure all processes
are terminated then try again. If it still fails, a git process
may have crashed in this repository earlier:
remove the file manually to continue.

Upon deletion of that lock file:

```
Z:\software\pandas>git checkout -f HEAD
error: unable to create file asv_bench/asv.conf.json: No such file or directory
fatal: cannot create directory at 'asv_bench/benchmarks': No such file or directory

```