Move shebang to top of file. (#458)

It otherwise has no effect, causing the default shell to be tried (which
is /bin/sh on my home system).

Author: rsgowman

lint.sh

@@ -1,3 +1,5 @@
+#!/bin/bash
+
 # Copyright 2017 Google Inc.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -12,8 +14,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-#!/bin/bash
-
 function lintAllFiles () {
   echo "Running linter on module $1"
   pylint --disable=$2 $1