Make blimp_engine_bundle action silent when successful.

blimp/tools/bundle-engine.py

Index: blimp/tools/bundle-engine.py
diff --git a/blimp/tools/bundle-engine.py b/blimp/tools/bundle-engine.py
index 62151ec73f0d648cbe33112fa9205811c70f7e83..911e4db8fab8866621a10779b54638c1274cb520 100755
--- a/blimp/tools/bundle-engine.py
+++ b/blimp/tools/bundle-engine.py
@@ -14,6 +14,7 @@ import argparse
 import errno
 import os
 import subprocess
+import sys
 import tarfile
 
 def ReadDependencies(manifest):
@@ -60,9 +61,8 @@ def main():
         tarball.add(dep)
       except OSError as e:
         if e.errno == errno.ENOENT:
-          print dep + " not found (did you build the engine?)"
+          print >> sys.stderr, dep + " not found (did you build the engine?)"
           exit(1)
-  print 'Created ' + args.output
 
 if __name__ == "__main__":
   main()