Increased timeout for Heat OSTF test
Increased timeout for Heat OSTF test

It looks like Heat OSTF test has small timeouts for
operations with stack and we need to increase timeouts
to avid false-negative results.

Change-Id: Ia24fda69682c7e079414f725fe78b5484a191d35
Closes-Bug: #1567727

stackforge/fuel-ostf,stackforge/fuel-ostf