Use configManager to handle configuration, not env vars

[nicobarray]

Currently we can set the logger's level with the AQUEDUX_LOG_LEVEL env var and also through the createAqueduxClient(store, option) 2nd parameter.

It would be better to handle configuration in a single spot - the configManager. If someone wants to use an env var he can use it to parameterize the said option parameter.

Todo:

• Track down all used environement variables and translate them to configManager options.
• Update the documentation to reflect all new options