This allows users to change the default logging verbosity (errors)
to either *detailed* (prints SQL statements) or *silent*.
Also added support for using a custom logger function.
- Fixed the gorm unit test that checks the automigrations
They will actually fail if any errors were logged now.
- Added a postgres unit test
Currently disabled because it would need a running local
postgres db and a change to the .travis.yml file to work
inside the CI build.
- The db test will run an sqlite3 database in in-memory
mode and run the automigrations.
- The template test will check if all the templates
that are stored in package variables (template.Must)
compile and if ReloadTemplates works without panicking.
