Attempt to fix test_commit_only and pass file before option

https://travis-ci.org/sdg-mit/gitless/jobs/213617137#L723

Author: techtonik

gitless/tests/test_e2e.py

@@ -181,7 +181,7 @@ def test_commit_relative(self):
     self.__assert_commit(self.TRACKED_FP, self.DIR_TRACKED_FP)
 
   def test_commit_only(self):
-    gl.commit(o=self.TRACKED_FP, m='msg')
+    gl.commit(self.TRACKED_FP, '-m="msg"')
     self.__assert_commit(self.TRACKED_FP)
 
   def test_commit_only_relative(self):