Switch conf settings to oslo.config

This commit switches all the config options to use oslo.config instead
of optparse. This enables optionally creating a config file to specify
certain environmental options. (such as user, ssh-key, etc..) The cli
options and functionality remain unchanged with this commit.
Make oslo.config optional

This commit changes oslo.config from being a mandatory requirement to
being optional. If importing oslo.config fails then it will default
back to using the optparse method of reading arguments. (and config
files won't be useable)
Fix typo with calling opt_parse()
Merge branch 'matt'