Merge dhcp_checker into network_checker

Related to blueprint combined-network-checker-and-dhcpchecker

Change-Id: Ie6bdfdb326b4f887f9a2a36a6a2b240cefd7f11b
Ability to run OSTF against user defined deployment

In order to run certain OSTF test multiple time you
need to set DEPLOYMENT_NAME environment variable.
Other variables should be set same way as in ordinary
system tests run.

Change-Id: I6cf70270acb2fd9deca1efd7eb6caad36b77daf8
Simple with cinder in one case

Change-Id: Ie2bda76d86b2dc5081ad6bb5359e4b6c0d96b2c2
Delete node / delete environment should use env snapshot

It turned out there is no need to deploy simple environment
for delete xxx tests.

Change-Id: I518f861ffa8955bbe29013ca9313641a1f82fef3
Set timeout for OSTF savana tests in deploy_savanna_simple

Change-Id: I883a4eff2f4ced3ba51162d2b4c6306603846d4c
Merge "Merge dhcp_checker into network_checker"
Merge "Delete node / delete environment should use env snapshot"
Merge "Set timeout for OSTF savana tests in deploy_savanna_simple"
Merge "Ability to run OSTF against user defined deployment"
Use a new ruby 2.1 in the master node as a single ruby version

* remove unused gems;
* remove rbenv env;
* remove ruby compilation.

Change-Id: I099e65901ef3cf691f90d5bda4dd2f1a5cb76ea7
Implements: blueprint fuel-new-system-ruby-in-master-node