Use assertTrue and assertFalse vs assertEqual

Using assertTrue and assertFalse is more readable while
checking a boolean result.

Note: In the following files we have to use assertEqual,
      since the api returns the value as unicode:
tempest/api/volume/test_volumes_get.py
65:            self.assertEqual('true', fetched_volume['bootable'])
65:            self.assertEqual('true', fetched_volume['bootable'])
114:            self.assertEqual('true', updated_volume['bootable'])
114:            self.assertEqual('true', updated_volume['bootable'])
tempest/api/volume/test_volumes_list.py
188:            self.assertEqual('false', volume['bootable'])
tempest/api/volume/test_volumes_get.py
67:            self.assertEqual('false', fetched_volume['bootable'])
116:            self.assertEqual('false', updated_volume['bootable'])
tempest/api/compute/servers/test_servers_negative.py
533:        self.assertEqual('false', nonbootable_vol['bootable'])

Change-Id: I004a7860847e8361280d3fa105d2dfa97d99bee4
3 files changed