fixed null issue
"Dashboard changes removed for teacher view."
Validations added for scoreHeder in DashBoard.
Merge remote-tracking branch 'upstream/dev-branch' into dev-branch

Conflicts:
	src/main/java/org/ednovo/gooru/client/mvp/classpages/unitdetails/UnitAssignmentView.java
Merge pull request #1640 from nutan-gooru/dev-branch

fixed null issue
Merge pull request #1641 from mitraj/dev-branch

Validations added for scoreHeder in DashBoard.
Merge pull request #1642 from sravanthi1/dev-branch

"Dashboard changes removed for teacher view."
Resolved conflicts.

Conflicts:

src/main/java/org/ednovo/gooru/client/mvp/classpages/unitdetails/UnitAssigmentReorder.java

src/main/java/org/ednovo/gooru/client/mvp/classpages/unitdetails/UnitAssignmentView.java