Don't use `override_time` but mock instead

Closes-bug: #1266962

We're moving away from using the set_override_time function in
timeutils. The right way to do it should be by using mock.

Change-Id: Ic69c5c5d66cb39d668015c368add10b108684549
Sync oslo-cache from oslo-incubator

This patch removes Marconi's local copy of the oslo-incubator cache
work. The patch also removes the memcached backend, although the version
coming from oslo doesn't have support for it yet. The backend will be
pulled in again as soon as it is updated upstream.

Change-Id: I487b2178d9657eb7abe020f06436b14531bdb993
fix: Move decorator out of class definition since it is static

This patch fixes a pylint error in one of the functional tests.

Change-Id: Ie90fb475f0861445d367e65ab38f8a2555c1a0ed
Drop msgpack dependency

We've been using msgpack just to pack the API document into sqlite
binary documents. This is easily achievable with json. We can pull
msgpack in again when there's a real use case for it.

Change-Id: I60e31806edafd71de62a1809f047a8ad772094cc
chore: Add pylint envs

This patch adds lint2 and lint3 testenvs to tox.ini for running pylint
under Python 2.7 and Python 3.3, respectively.

Change-Id: Ia73ce61fc19b0e30a6de5ad90236d41dbbf33125
Merge "Sync oslo-cache from oslo-incubator"
Merge "Don't use `override_time` but mock instead"
Add a _config_options function to Marconi

This function is necessary for options discoverability and manual
options registration. This first patch adds a config function to every
module defining options in marconi. Those functions were registered as
entrypoints that will then be loaded by the configuration sample
generator.

Change-Id: I2c351c14c7e1b104926162336ed3567696c62dfb
Merge "fix: Move decorator out of class definition since it is static"
Merge "chore: Add pylint envs"