Implements CA Provider checks and places keylime.conf
Implements CA Provider checks and places keylime.conf

This change places keylime.conf into /etc (if root user), if not
informs user they need the file present (if keylime.conf is not in
place)

It also introduces a new arg -s or --ssl openssl|cfssl

This allows both options for testing both ca_impl functions.

Closes #21

mit-ll/python-keylime,mit-ll/python-keylime,mit-ll/python-keylime,mit-ll/python-keylime