tests: remove unused import
cmds: strip comments from commit messages

Git automatically strips comments from commit messages, but not when the
"-F" flag is used to specify a commit message file.

Strip the commit message before handing it off to Git.

Signed-off-by: David Aguilar <davvid@gmail.com>
cmds: move execution of "git commit" into the Commit command

Make things simpler by removing an unneeded layer of indirection.

Signed-off-by: David Aguilar <davvid@gmail.com>