Merge pull request #4668 from edx/nedbat/require-release

Require OPENEDX_RELEASE

CHANGELOG.md

+- Installation
+  - OPENEDX_RELEASE is now required, to prevent accidental installation of master.
+
 - XQueue
   - Expose CLOUDWATCH_QUEUE_COUNT_METRIC which is defined XQueue's settings.py for further dictionary structure
 

util/install/sandbox.sh

@@ -9,11 +9,17 @@
 ##
 
 ##
-## Sanity check
+## Sanity checks
 ##
+
+if [[ ! $OPENEDX_RELEASE ]]; then
+    echo "You must define OPENEDX_RELEASE"
+    exit
+fi
+
 if [[ `lsb_release -rs` != "16.04" ]]; then
-   echo "This script is only known to work on Ubuntu 16.04, exiting...";
-   exit;
+    echo "This script is only known to work on Ubuntu 16.04, exiting..."
+    exit
 fi
 
 ##