removing some cruft

[ndushay]

These are the only potentially worthy things to carry over from my aborted work at a separate sinopia_client git repo.

• .gitignore: removes copy-pasta cruft from Taco(?) .gitignore
• sinopia_client/git_push.sh: removed as it was a one shot and probably wasn't meant to be in the repo in any case (per @jmartin-sul)

@jermnelson should there be a ticket for getting sinopia_client tests to run as part of circle_ci build, or is that done already or ...?

[jermnelson]

Hi @ndushay, testing the client is already part of the CI build; see https://github.com/LD4P/sinopia_server/blob/master/.circleci/config.yml#L18-L35