Merge pull request #186 from vladimir-v-diaz/develop

Address Issues #175, #176, and the installation of TUF.
Reviewed by Trishank.
Update README.md
Update README.md
Merge branch 'develop' of https://github.com/vladimir-v-diaz/tuf into develop
Finish refactor of test_updater.py.

test_updater.py now uses repository_tool.py to update the remote repository as needed, and no longer depends on mocking and repository_setup.py.