Issue #22 - Automatically process the expected number of commits
If -c (number of commits) is not provided, it will default to 1. We could make it retrieve the number of commits that matches the bug number of the first (HEAD) commit.
Say we have the following git log: Bug 12345: commit 3 Bug 12345: commit 2 Bug 12345: commit 1 Bug 54321: something else
We default to 3.