json syntax fix; standardize env names to {dev, stage, prod}

cloudformation_templates/edx-reference-architecture.json

@@ -4,7 +4,7 @@
   "Parameters":{
     "EnvironmentTag":{
       "Type":"String",
-      "Description":"A tag value applied to the hosts in the VPC indicating which environment to use during the configuration phase, e.g., development, stage, production",
+      "Description":"A tag value applied to the hosts in the VPC indicating which environment to use during the configuration phase, e.g., dev, stage, prod",
       "Default":"stage"
     },
     "KeyName":{
@@ -3162,7 +3162,7 @@
                 "AZone0"
               ]
             }, " ",
-            "--cache-parameter-group-name default.memcached1.4 "
+            "--cache-parameter-group-name default.memcached1.4 ",
             "--auto-minor-version-upgrade true ",
             "--cache-subnet-group-name ", { "Ref":"EdxVPC" },"-ElasticCacheSubnetGroup"
           ]