Fixes a typo in run_tests.py and its test (by Vlad Losev).

run_tests.py

@@ -191,7 +191,7 @@ class TestRunner(object):
     if self.subprocess:
       return self.subprocess.Popen(args).wait()
     else:
-      return self.os.spawn(self.os.P_WAIT, args[0], args)
+      return self.os.spawnv(self.os.P_WAIT, args[0], args)
 
   def RunBinaryTest(self, test):
     """Runs the binary test script given its path relative to the gtest root.

test/run_tests_test.py

@@ -124,7 +124,7 @@ class FakeOs(object):
     assert self.path.isdir(path)
     return self.path.PathElement(path).iterkeys()
 
-  def spawn(self, wait, executable, *kargs):
+  def spawnv(self, wait, executable, *kargs):
     assert wait == FakeOs.P_WAIT
     return self.spawn_impl(executable, kargs)