Update stubbing of GitHub API in tests

Prior to this commit, one of the calls to the GitHub API
(organization_member?) was not being stubbed in the tests which
caused failures due to API rate limits.

Now the return value of this method is stubbed to always be "true"

WIP Move views and public to the root of the project
Reorganize file structure

Prior to this commit, both the public and views directories were
stored in the lib directory. This was because Sinatra looked for them
in a specific place relative to the server file.

Now they have been relocated and the path Sinatra will use to locate
them has been reconfigured.