Add devstack-version script

This will help in collecting information about the devstack version
being used.

Change-Id: I23a8ca023bda6d097051cd57ae45401806451ad5

functions

@@ -751,6 +751,21 @@ function get_random_port {
 }
 
 
+function write_devstack_version {
+    pushd $TOP_DIR
+    local git_version=""
+    git_version=$(git log --format="%H %s %ci" -1)
+    cat - > /tmp/devstack-version <<EOF
+#!/bin/bash
+
+echo "DevStack Version: ${DEVSTACK_SERIES} - ${git_version}"
+echo "OS Version: ${os_VENDOR} ${os_RELEASE} ${os_CODENAME}"
+
+EOF
+    sudo install -m 755 /tmp/devstack-version /usr/local/bin/devstack-version
+    rm /tmp/devstack-version
+}
+
 # Restore xtrace
 $_XTRACE_FUNCTIONS
 

stack.sh

@@ -216,6 +216,9 @@ if [[ ! -r $TOP_DIR/stackrc ]]; then
 fi
 source $TOP_DIR/stackrc
 
+# this installs a devstack-version script to make it easy to report the version back
+write_devstack_version
+
 # 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|rhel7|kvmibm1) ]]; then
@@ -1521,19 +1524,28 @@ fi
 
 # Warn that a deprecated feature was used
 if [[ -n "$DEPRECATED_TEXT" ]]; then
-    echo_summary "WARNING: $DEPRECATED_TEXT"
+    echo
+    echo -e "WARNING: $DEPRECATED_TEXT"
+    echo
 fi
 
 # If USE_SYSTEMD is enabled, tell the user about using it.
 if [[ "$USE_SYSTEMD" == "True" ]]; then
+    echo
     echo "Services are running under systemd unit files."
     echo "For more information see: "
     echo "https://docs.openstack.org/developer/devstack/systemd.html"
+    echo
 fi
 
+# devstack version
+devstack-version
+echo
+
 # Indicate how long this took to run (bash maintained variable ``SECONDS``)
 echo_summary "stack.sh completed in $SECONDS seconds."
 
+
 # Restore/close logging file descriptors
 exec 1>&3
 exec 2>&3

stackrc

@@ -272,6 +272,7 @@ REQUIREMENTS_DIR=$DEST/requirements
 # Setting the variable to 'ALL' will activate the download for all
 # libraries.
 
+DEVSTACK_SERIES="pike"
 
 ##############
 #