Fix few spelling and grammar errors

Change-Id: I8e678a9f76cba3d90053d28baf4ff42d34b4e390

taskflow/atom.py

@@ -32,7 +32,7 @@ def _save_as_to_mapping(save_as):
     Result should follow storage convention for mappings.
     """
     # TODO(harlowja): we should probably document this behavior & convention
-    # outside of code so that its more easily understandable, since what an
+    # outside of code so that it's more easily understandable, since what an
     # atom returns is pretty crucial for other later operations.
     if save_as is None:
         return {}

taskflow/persistence/backends/impl_zookeeper.py

@@ -345,7 +345,7 @@ class ZkConnection(base.Connection):
                 yield self._get_logbook(lb_uuid)
 
     def destroy_logbook(self, lb_uuid):
-        """Detroy (delete) a log_book transactionally."""
+        """Destroy (delete) a log_book transactionally."""
 
         def _destroy_task_details(td_uuid, txn):
             td_path = paths.join(self.task_path, td_uuid)

taskflow/tests/unit/persistence/base.py

@@ -56,7 +56,7 @@ class PersistenceTestMixin(object):
         lb.add(fd)
 
         # Ensure we can't save it since its owning logbook hasn't been
-        # saved (flow details can not exist on there own without a connection
+        # saved (flow details can not exist on their own without a connection
         # to a logbook).
         with contextlib.closing(self._get_connection()) as conn:
             self.assertRaises(exc.NotFound, conn.get_logbook, lb_id)
@@ -97,8 +97,8 @@ class PersistenceTestMixin(object):
         fd.add(td)
 
         # Ensure we can't save it since its owning logbook hasn't been
-        # saved (flow details/task details can not exist on there own without
-        # there parent existing).
+        # saved (flow details/task details can not exist on their own without
+        # their parent existing).
         with contextlib.closing(self._get_connection()) as conn:
             self.assertRaises(exc.NotFound, conn.update_flow_details, fd)
             self.assertRaises(exc.NotFound, conn.update_task_details, td)

taskflow/tests/unit/persistence/test_sql_persistence.py

@@ -251,7 +251,7 @@ class PostgresPersistenceTest(BackendPersistenceTestMixin, test.TestCase):
     def _reset_database(self):
         engine = None
         try:
-            # Postgres can't operate on the database its connected to, thats
+            # Postgres can't operate on the database it's connected to, that's
             # why we connect to the default template database 'template1' and
             # then drop and create the desired database.
             db_uri = _get_connect_string('postgres', USER, PASSWD,

taskflow/utils/threading_utils.py

@@ -31,6 +31,6 @@ def get_optimal_thread_count():
         return multiprocessing.cpu_count() + 1
     except NotImplementedError:
         # NOTE(harlowja): apparently may raise so in this case we will
-        # just setup two threads since its hard to know what else we
+        # just setup two threads since it's hard to know what else we
         # should do in this situation.
         return 2