Do a git fetch instead of pull

Author: honzakral

test_elasticsearch/run_tests.py

@@ -54,7 +54,7 @@ def fetch_es_repo():
  shell=True,
  )
  # reset to the version fron info()
- subprocess.check_call("cd %s && git pull" % repo_path, shell=True)
+ subprocess.check_call("cd %s && git fetch" % repo_path, shell=True)
  subprocess.check_call("cd %s && git reset --hard %s" % (repo_path, sha), shell=True)