Add f26 to the supported distros

The only mentionable diff is the kvm alias
does not exists so we will install
qemu-kvm as with rhel7 which also exists
in the older supported fedoras.

kvm also just an alias in suse so
switching to qemu-kvm  in suse as well.

Change-Id: I5c79ad1ef0b11dba30c931a59786f9eb7e7f8587
diff --git a/stack.sh b/stack.sh
index b786f7b..2ceb933 100755
--- a/stack.sh
+++ b/stack.sh
@@ -221,7 +221,7 @@
 
 # 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|opensuse-42.2|opensuse-42.3|rhel7|kvmibm1) ]]; then
+if [[ ! ${DISTRO} =~ (xenial|yakkety|zesty|stretch|jessie|f24|f25|f26|opensuse-42.2|opensuse-42.3|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"