Merge remote-tracking branch 'gooru/master'
Merge pull request #441 from cyrilraja/master

*CORE-1235 implemented for throwing error while update existing url
Added fix for 6.5.a [Library - RUSD] Feature course content missing
Merge remote-tracking branch 'gooru/master'
Merge branch 'master' of https://github.com/cyrilraja/Gooru-Core-API
Merge pull request #455 from skpcharles/master

Added fix for 6.5.a [Library - RUSD] Feature course content missing
Merge pull request #457 from cyrilraja/master

*refactored variable names in classpage
Merge remote-tracking branch 'gooru/master'
added constants for Controllers