* Fix the gitlab oauth issue.

* Update for gitlab 11.1+

Versions beyond 11.1 (and possibly a few releases before) use a
different method for delivering tokens.  They also have disabled
version 3 of the api.

These changes address that and add a debugging mode for the server
that make it easier to debug issues like this in the future.

* Cleanup of PR.

Updated README. Removed code duplication.

Microsoft uses JSON Web Tokens (JWT) as OAuth tokens. These can run to many thousands of characters which are too long for TTYs. Work around this by base64-encoding the token and chunk it into smaller pieces.

Closes #70 

This hasn't been enabled in a while due to gRPC limitations

- Add `fast_finish` to travis config
- Specify that Go 1.9 is supported
- Additional error checking which was previously missed
- Make the migrations test better
-

It's currently hard to make changes to the database schema. Use sql-migrate to make incremental changes.
Stop hard-coding the database name (the default is still "certs" for backward-compatibility)
The `automigrate()` function will automatically run pending migrations.
Use a different migration directory per database driver. This carries a cost of duplication, but is easier than creating migrations which will cleanly execute in both SQLite and MySQL.
Migrations are shipped using the packr utility.