While building proxmark3 in an environment without `git` installed, I
noticed the following errors on stderr:
```
mkversion create test env: 'git': No such file or directory
stat: cannot statx '../README.md': No such file or directory
```
The first line "env: 'git': No such file or directory" is expected, as
git is not installed.
However, the second line "stat: cannot statx '../README.md': No such
file or directory" is a real error: we're running from top-level
directory, so the correct path for README.md is just "README.md".