hs-test: added dry run mode

- DRYRUN=true will set up most containers. Some need to be started
  manually (curl, nginx...). The framework will create a vpp-config
  file with interface configs that will get executed on VPP startup.
- set Ginkgo to use -v instead of -vv when running a single test
- s.Log() now supports formatting
- added 'useEnvVars' parameter to container.Exec

Type: test

Change-Id: Id1da7947a1448ee4b74b86cc4f243442256a5ba8
Signed-off-by: Adrian Villin <avillin@cisco.com>

extras/hs-test/script/compress.sh

@@ -1,5 +1,10 @@
 #!/usr/bin/env bash
 
+if [ $1 == 2 ]
+then
+    exit 1
+fi
+
 # if failed-summary.log is not empty, exit status = 1
 if [ -s "${HS_ROOT}/summary/failed-summary.log" ]
 then