Fix Brick LVM test command parsing

The case reporting only one fake-volumes VG was never hit, which also
caused us to not test the lvcreate -T path.

Change-Id: If43d6aff5f90d6eca24b3df790d8ad3a86bfc8f3
Drop Chance/SimpleScheduler Implementation

This patch removes the implementation of ChanceScheduler and SimpleScheduler
as previous changes have made sure they are internally replaced by
FilterScheduler.

The "max_gigabytes" config option is deprecated and will leave it like that
for one more release before we can remove it.

DocImpact: "ChanceScheduler and SimpleScheduler have been deprecated and
their implementation have been removed from Cinder."

Implement bp: deprecate-chance-and-simple-schedulers

Change-Id: Ifb1cb25e3bb4cdf26fa3283336b83fce5c97141e
Print driver exception on retype

If the driver raises an exception, make sure it is printed. Also change
the logging level from info to error because an exception should not be
thrown under normal conditions.

Change-Id: I003959c3f7c7667124ef61911587012fd4e1d667
Closes-Bug: #1268294
Merge "Drop Chance/SimpleScheduler Implementation"
Merge "Fix Brick LVM test command parsing"
Merge "Print driver exception on retype"