Bump version to 0.11.0-alpha.1
Bump version to 0.11.0-alpha.1

Bumping this to put it in production for a while. This is a very solid
candidate for a 1.0. If we don't find anything, we will release 1.0
next week

Signed-off-by: Daniel Magliola <89d49b6744ccc763daa8041f77a567a08347f890@gocardless.com>

prometheus/client_ruby