Often in the SDK, we would like to run certain code every-so often. The purpose of epochs
module is to allow other modules to set that they would like to be signaled once every period. So another module can specify it wants to execute code once a week, starting at UTC-time = x. epochs
creates a generalized epoch interface to other modules so that they can easily be signalled upon such events.
This module is modified from the x/epochs
module of Osmosis. See the LICENSE for more details about usage.