add some tests

[ssoroka]

Would be great to have some tests in place so there's some confidence that this stays working. Would also likely improve the code structure.

[rwynn]

@ssoroka thanks for trying gtm. I would love to add tests to this project but currently don't have the spare time to do so. If I do get some time I will add something probably based on the docker tests at

https://github.com/rwynn/monstache/tree/master/docker/test

which indirectly tests gtm by testing monstache - realtime sync between MongoDB and Elasticsearch

• via docker-compose for ease of replication.

Would probably start with that as a base, remove the Elasticsearch stuff, increase the version coverage of MongoDB, and write a test driver like the one here...

https://github.com/rwynn/monstache/blob/master/monstache_test.go

If you have time to do something like this I would appreciate it as a PR. If not, I will try to get to it when possible.

You may have been referring more to unit tests instead of functional tests. If so I agree those would be great also.