Add bootstrap to the partner app

[davidsth]

We will need to add the bootstrap gem to the Gemfile (https://github.com/twbs/bootstrap-rubygem)

We have a basic login form we would like to apply bootsrap styling (/partners/sign_in)

[segunadeleye]

I would love to pick up this issue and work on it.

[davidsth]

I would love to pick up this issue and work on it.

@segunadeleye Hey looks like someone already made a PR to it. I've created a new issue to apply css styling to the login form if you're interested! #14

[segunadeleye]

@davidshr10 I later realised someone already picked it up. I am just seeing the message about the other issue. I think someone also picked that up but yet to raise a PR. Perhaps I could still pick it up.