Run some unit test cases based (poorly) around sodium's test infrastructure.
Increase in unity test task stack is due to signature tests, load a lot of data onto the stack.
This change adds gitlab CI support. It tests if latest master of esp-idf-template can be built with the commit of ESP-IDF in question. Currently it's a bit lax because both SDK_PATH and IDF_PATH are defined.
This change also changes components/esp32/lib submodule to point to Github over HTTPS instead of SSH, because CI server might not have its SSH keys uploaded to Github.
