Minor improvements

[plambert]

Not sure if anyone else is using this, but I've improved a few minor things. If it would be better to break them out into separate PRs, I'm happy to do that, just let me know.

• Moved syntax from tmLanguage to sublime-syntax format
• Removed a lot of ruby-specific leftovers
• Indent after enum correctly
• Support syntax tests for the Crystal sublime-syntax file
  • Don't auto-format syntax_test_*.cr files (only helpful if you're working on the crystal syntax…)
  • Added an ameba.yml configuration file, though I don't think it fixes the problem--I had to patch SublimeLinter-contrib-ameba…
• Improve support for CRYSTAL heredocs
• Rename sublime-snippet files to say Crystal instead of Ruby