Appveyor: link to status of the master branch, not the whole project
Tweak ESLint options
Actually lint the lib folder (doh!)
Support Git URLs with server tags

When a dependency is a Git URL that contains a valid semver tag, then
check-dependencies will also run its checks.

* The tag is also considered valid when prefixed with 'v' as it is common
pratice.
* Updated tests (ok and not ok) and added others specific to git urls
* Dont ignore node_modules in fixtures because we need them for the tests