Enable opensuse-42.2 as a tested distro

openSUSE 42.2 passes testing on the experimental gate and
in order to add it as continuosly tested target we need to
add it to the positive list of tested distributions.

Change-Id: I46f94cfad828534f324994c3d21bddff40e8f9a2
diff --git a/stack.sh b/stack.sh
index 83da1c6..8989ad6 100755
--- a/stack.sh
+++ b/stack.sh
@@ -192,7 +192,7 @@
 
 # Warn users who aren't on an explicitly supported distro, but allow them to
 # override check and attempt installation with ``FORCE=yes ./stack``
-if [[ ! ${DISTRO} =~ (xenial|yakkety|zesty|stretch|jessie|f24|f25|rhel7|kvmibm1) ]]; then
+if [[ ! ${DISTRO} =~ (xenial|yakkety|zesty|stretch|jessie|f24|f25|opensuse-42.2|rhel7|kvmibm1) ]]; then
     echo "WARNING: this script has not been tested on $DISTRO"
     if [[ "$FORCE" != "yes" ]]; then
         die $LINENO "If you wish to run this script anyway run with FORCE=yes"