Consider using Transifex #615
Description
Transifex is used by several translations, and personally I am a fan.
We (python transifex team) have documentation on how to set up, this is however made much easier with sample-workflows, create tx key, and change the config to your language. For an example see: repo
Note that you will have to push all of your existing translation using the tx cli to transifex.
If you have any further questions do not hesitate to ask.