Move Codeship DB Parameters to a separate file #379

Codeship doesn't seem to pick up our values & the environment, so
we'll leave them with a separate file `database.yml_codeship`.

Also add a template to the standard database.yml_example, as the
postgres gem does seem to care about it:

  PG::InvalidParameterValue: ERROR:  new encoding (UTF8) is
  incompatible with the encoding of the template database (SQL_ASCII)
  HINT:  Use the same encoding as in the template database,
  or use template0 as template.