Don't need to init testr explicitly

In run_tests.sh, function init_testr will initialize testr if the
directory .testrepository is not existed. Actually, testr will do
the check before run the test:

In Python package testrepository, setuptools_command.py:Testr.run

68 def run(self):
69 """Set up testr repo, then run testr"""
70     if not os.path.isdir(".testrepository"):
71         self._run_testr("init")

"python setup.py testr" will trigger this function to create
.testrepository if not exist.

So, init_testr can be removed safely.

Fixes Bug #1220149

Change-Id: I4dfcdfa5e1e323bbc7ee3add5d9d0888a42e3812

run_tests.sh

@@ -72,11 +72,6 @@ if [ $no_site_packages -eq 1 ]; then
   installvenvopts="--no-site-packages"
 fi
 
-function init_testr {
-  if [ ! -d .testrepository ]; then
-    ${wrapper} testr init
-  fi
-}
 
 function run_tests {
   # Cleanup *.pyc
@@ -179,7 +174,6 @@ if [ $just_flake8 -eq 1 ]; then
     exit
 fi
 
-init_testr
 run_tests
 
 # NOTE(sirp): we only want to run flake8 when we're running the full-test suite,