For example, will handle an entire directory tree of files, linking all
files:
```
- link:
~/.config/:
path: dotconf/config/**
glob: true
```
NOTE, this feature requires newer versions of `glob()` (Python >= 3.5),
and `dotbot` will throw an error if using an earlier version of python.
For testing purposes, added:
- ability to skip tests in test harness
- added testing for older Python(s).
FIXES: #270
