file permissions 755 -> 644
Merge pull request #7 from zendesk/sdavidovitz/permissions

file permissions 755 -> 644
Add Google as an authentication option.

Requires GOOGLE_CLIENT_ID and GOOGLE_CLIENT_SECRET to be present in the
.env file.
Update readme to include Google authentication config.

Refactored the config section of the readme to make it a bit more
obvious how to generate the OAuth tokens and which parts are optional /
mandatory.
Swap order of Google and Zendesk authentication options.
Correct line spacing at the end of omniauth file.

Applying coding convention fix from pull request.