Handle invalid version with dots

[jeffwidman]

This adds a test case for an invalid version with dots.

We expect the test to pass, but today it fails with:

eval error: Malformed version number string 1.8.0-failed.release.attempt
  /usr/local/lib/ruby/site_ruby/2.7.0/rubygems/version.rb:214:in `initialize'
  /home/dependabot/dependabot-core/python/lib/dependabot/python/version.rb:43:in `initialize'
  /usr/local/lib/ruby/site_ruby/2.7.0/rubygems/version.rb:203:in `new'
  /usr/local/lib/ruby/site_ruby/2.7.0/rubygems/version.rb:203:in `new'
  (rdbg)//home/dependabot/dependabot-core/common/lib/dependabot/metadata_finders/base/commits_finder.rb:1:in `tag_matches_version?'

The relevant version pattern regex.

[sshishov]

I am having the same issue with yarl package

[jeffwidman]

Anyone else in the community is welcome to take a crack at this... this PR is essentially a "issue" that was opened as a PR to exercise CI.

It'd be a great first issue for anyone who wants to learn more about regex's.