Add orcid login option

[anusharanganathan]

Added Orcid omniauth and configured it Followed instructions from https://www.digitalocean.com/community/tutorials/how-to-configure-devise-and-omniauth-for-your-rails-application https://github.com/datacite/omniauth-orcid

Commit 2f1ea3305153f1c054748166c645e102b2bc2a3f

Have 2 outstanding issues

• [x] The redirect url to the omniauth provider doesnot include https
• [x] Getting the error message invalid credentials supplied after accepting and allowing application access

[anusharanganathan]

The url should match https://cloud.digitalocean.com/v1/oauth/authorize?client_id=9dfec7624ee71b2c49c5b4f15c04263199bfc12d677a7428b22b8cd2c5f4e2f6&redirect_uri=https://dev.data2paper.org/users/auth/digitalocean/callback&response_type=code&i=39cf66 for DO

[anusharanganathan]

I had an empty config/initializers/omniauth.rb which messed up devise. Removing it solved the errors. commit ef789f20b68d3a388297a5f0a0513af3c3d2bb93