Set swift timeouts higher

Devstack is commonly run in a small slow environment, so bump the
timeouts up.

node_timeout is how long between read operations a node takes to
respond to the proxy server
conn_timeout is all about how long it takes a connect() system call to
return

Change-Id: Ib437466a3fc9274b8aa49b19e4fe7fa26f553419
Co-Authored-By: Peter Portante <peter.portante@redhat.com>
Related-Bug: #1252514
Check if flavors exist before creating them.

* lib/tempest: When creating the m1.tiny and m1.nano flavors ensure that
they don't exist first. This is important for Grenade where code may be
run multiple times and should expect that some things preexist.

Change-Id: I1772d4334f39d612f8a187eb5311a1b2caee3953
Merge "Check if flavors exist before creating them."