Protected requirements.txt references

For certain install profiles, in order to avoid the following prompt:

  Cloning git@gitlab.syncad.com:hive/hivemind.git (to ba54fc07c08c2fd08b37475c9a15d61c64e380c9) to ./src/hivemind
git@gitlab.syncad.com's password:

In requirements.txt ...

Suggest changing this:

-e git+https://gitlab.syncad.com/hive/hivemind.git@ba54fc07c08c2fd08b37475c9a15d61c64e380c9#egg=hivemind

To this:

-e git+git@gitlab.syncad.com:hive/hivemind.git@ba54fc07c08c2fd08b37475c9a15d61c64e380c9#egg=hivemind