Fix wrong initialization of AuthPlugin for keystone v3

Ceilometerclient doesn't pass domain related arguments to AuthPlugin,
which will cause keystoneclient v3 cannot be used properly.

Change-Id: I2554a36f214c0eae61b7ba6b8580c41b8f8c6370
Closes-Bug: #1391122
Add --slowest option for testr

Enable --slowest option for testr, so we can observe the worst
performance unit test cases of all.

Change-Id: I7a5ce4b44a3571da9156a37657d16c8a2f468319
Refactor tests/test_shell.py

Remove unnecessary help test for keystone shell test.

Change-Id: I4891a3e7d13f924ba0a1f7c57e87cd092ed8f9ff
Closes-Bug: #1391965
Fix timeout argument not treated as integer

Currently, if we specify --timeout 30 in CLI commands. we will get
'a float is required' error. Since we already specify timeout is
ingeter in ceilometer.v2.client, this patch converts CLI argument
timeout to integer.

Note, if zero is passed to v2.client, we treat it as disable timeout.

Change-Id: I213b6c24964095297cb4e87c25bb871ebd668bb4
Closes-Bug: #1391606
Merge "Add --slowest option for testr"
Merge "Fix wrong initialization of AuthPlugin for keystone v3"