Add gem description

Signed-off-by: Lewis Marshall <lewis@lmars.net>
Add Lewis Marshall to gem authors

Signed-off-by: Lewis Marshall <lewis@lmars.net>
Update gem license

Signed-off-by: Lewis Marshall <lewis@lmars.net>
Move the RPCClient into a gem

Signed-off-by: Lewis Marshall <lewis@lmars.net>