move upload code for assets to AssetsView
STUD-1523
Revert "added and updated pavelib/quality.py from dglance branch, deprecated rake quality tasks"

This reverts commit 7fd2305f395ef0ca2e699d4ed1c0a78ba8e46136.
Merge pull request #3850 from edx/zoldak/revert-paver-quality

Revert "added and updated pavelib/quality.py..."
Merge pull request #3306 from edx/zub/bugfix/std1523-uploadassetbutton

move upload asset code for assets to AssetsView