Bugfix/custom url is not working on docker

[WozniakMac]

If you try to use Mirage with docker it will fail because:

1. In Mirage.start (runner.rb:14) it put default port. After that in Mirage::Client this if elsif (client.rb:15) will never use custom url because at first it check if there is port and if it could find it localhost is used.
2. In Runner.start it use Mirage.running?(options) - (runner.rb:91) with Hash type param. Because of that it will always try to find if app is running as localhost not u custom url.

I tried to fix this error with backward compatibility. Classes interface stay almost this same.

[WozniakMac]

CI is broken