Modify commit sha format to allow more than 7 digits

Currently, commit sha format allows only 40 digits, like this:

• @57f649e84a45f60e74391141a2c53cf8018735e5

This patch allows more than 7 digits, like following.

• @57f649e

Please modify or drop this patch for your style.

Main.hs

@@ -56,7 +56,10 @@ parseQuery =
   ]
   where
     maybeProj = optional project
-    commitSha = replicateM 40 hexDigitChar
+    commitSha = do
+      sha7 <- replicateM 7 hexDigitChar
+      shas <- replicateM 33 (optional hexDigitChar)
+      return $ sha7 ++ catMaybes shas
     project = do
       group1 <- letterChar
       group <- some projectNameChar