[feature] Execute collect static only when versions change

[nemesifier]

I have an idea of how we could deal with extreme slowness of calling collectstatic when using object storage:

• We could hash the output of pip freeze in the dashboard container
• Before calling collectstatic we check in redis to see if the current pip freeze hash is different from the one saved there
• If it's different we call collectstatic and then save the new hash in redis

@pandafy @atb00ker what do you think?

[atb00ker]

I think this would work! 😄

[pandafy]

I agree, this will surely reduce the time for bringing up new container.