fix json_format for python2.6:

1, objcect_pair_hook is not supported in python2.6, so duplicated key check is removed in 2.6
2, total_seconds is not suppoted in python2.6, changed to compute seconds directly

1 files changed, 1 insertions, 2 deletions

diff --git a/travis.sh b/travis.sh
index 6b050737..435e7e75 100755
--- a/travis.sh
+++ b/travis.sh
@@ -131,8 +131,7 @@ build_python() {
   cd python
   # Only test Python 2.6/3.x on Linux
   if [ $(uname -s) == "Linux" ]; then
-    # py26 is currently disabled due to json_format
-    envlist=py\{27,33,34\}-python
+    envlist=py\{26,27,33,34\}-python
   else
     envlist=py27-python
   fi