Remove provider keys from repository in Fake Data generator

Fake Data generator for enterprise demo is running on Jenkins. And it calls the MT api to generate fake data. This is needed and important for sales and demo.

We cannot leave the keys in the repo anymore. We need to remove them from here: https://github.com/3scale/system/blob/master/script/fake_data/fake_data.rb#L190

TODO:

• Create a related technical task on github.