Change print statements to work in python3

This is part of a series of changes to introduce Python3 support.

Change-Id: I373be5de7141aa127d7debdbce1df39148dbec32
diff --git a/git_command.py b/git_command.py
index e5e28f3..d347dd6 100644
--- a/git_command.py
+++ b/git_command.py
@@ -13,6 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from __future__ import print_function
 import os
 import sys
 import subprocess
@@ -92,7 +93,7 @@
             ver_str[len('git version '):].strip().split('-')[0].split('.')[0:3]
           ))
       else:
-        print >>sys.stderr, 'fatal: "%s" unsupported' % ver_str
+        print('fatal: "%s" unsupported' % ver_str, file=sys.stderr)
         sys.exit(1)
     return _git_version
 
@@ -111,7 +112,7 @@
     return True
   if fail:
     need = '.'.join(map(str, min_version))
-    print >>sys.stderr, 'fatal: git %s or later required' % need
+    print('fatal: git %s or later required' % need, file=sys.stderr)
     sys.exit(1)
   return False