fixed project path
Merge remote-tracking branch 'origin/master'
fixed package prefix for resource roots

Testing Done:
manually

Reviewed at https://rbcommons.com/s/twitter/r/1123/
respect relative paths in auto-import

Reviewed at https://rbcommons.com/s/twitter/r/1121/
fixed completion and tests

to use standart file references files should be in a project. in case of Pants we don't include them before they appear in a BUILD file that's why I've added a custom completion and didn't use ReferenceProvider.

also fixed running completion test with community python plugin. and add some tests for tab comletion.

Testing Done:
tests are green

Reviewed at https://rbcommons.com/s/twitter/r/1120/
handle invalid files
Changed ReadMe. 

Added Scala plugin installation instructions.
Update README.md
add a source root for common root modules.

I forgot to add a source root to a module node for common roots. :-)

Reviewed at https://rbcommons.com/s/twitter/r/1141/
fixed arguments parsing
initial tests for PantsResolver
handle multiple common roots

Testing Done:
tests!

+manually

Reviewed at https://rbcommons.com/s/twitter/r/1153/
add a source root for common root modules.

Added source for Combining scala-> java sources. Also changed logic to identify scala projects

Testing Done:
Manually done.

Reviewed at https://rbcommons.com/s/twitter/r/1152/
Add newly added modules to projectInfo

Testing Done:
Manually.

Your change did not add scala facet to newly added modules.

With this change scala facets are added to modules created using common_roots logics.
However i still see some failures.

Reviewed at https://rbcommons.com/s/twitter/r/1160/