1.5.0-rc.2

This is release candidate 2 for Rabix Composer 1.5.0 (1.5.0-rc.2) with the following enhancements and fixes:

Enhancements

1. Custom executor feature added (#420)
   1. Use any locally installed runner for CWL 1.x documents (must be explicitly set in settings)
   2. sbg:draft2 documents will automatically run on Rabix Executor only
2. Live logs feature implemented (#419)
3. BioData Catalyst platform added to platform list

Fixes

1. App push to project fails (#457)
2. Composer strips requirements from workflow (#465)