Remove the annoying danger complaint about the commit message line length of 50 characters and dot presence

We have discussed in #827 (closed) that we may potentially try to reconfigure danger to not require us to fit the commit message within the 50 characters line length. I am not in favor of allowing very very long commit messages but 50 characters seems short to me. If we can reconfigure it to 70-80 characters, fine. I'd be also fine with disabling this particular check. @slawek says it is possible.

We can also consider ignoring the warning message, so that the reviewer doesn't have to bother checking if the commit messages are fine by danger.