m1.tiny flavor is hard coded to some tests.
This flavor is not always there, for instance if I don't use devstack.
heat_integrationtests/prepare_test_env.sh creates m1.heat_int flavor
which is the same size as m1.tiny according to the document at
admin-guide/cli-manage-flavors.html
Change-Id: I36524e069eacb36c7e6e7e0297c600ee68be88d6