Replace assertTrue(isinstance()) with assertIsInstance()

Some of tests use different method of assertTrue(isinstance(A, B)) or
assertEqual(type(A), B). The correct way is to use assertIsInstance(A,
B) provided by testtools.
There has one more place should be modified.

Change-Id: I751a2fb79857c09952a59e29301bf54ff6482d01
Closes-bug: #1268480
1 file changed
tree: 49295e6ae8631f74da8a68dcac8bd135918b0826
  1. common/
  2. functional/
  3. scenario/