[Review Required] Fixing Licenses - Some more

[mbaijal]

Description

Fixing Licenses some more
@bhavinthaker @marcoabreu Please review

Note: For details, Please refer to this wiki - https://cwiki.apache.org/confluence/display/MXNET/MXNet+Source+Licenses

Checklist

Essentials

• Passed code style checking (make lint)
• Changes are complete (i.e. I finished coding on this PR)
• All changes have test coverage:
• To the my best knowledge, examples are either not affected by this change, or have been fixed to be compatible with this change

Changes

• appveyor.yml
• tests/ci_build/pylintrc

Please Review the following -

• correct comment markers are used for the new formats
• It is ok to add a license to these files (nothing will break)
• the updated files do fall under the Apache license
• Please help make sure that NO CODE has been affected in this PR (only blank spaces and comments)