Merge pull request #2757 from edx/feanil/update_sandbox_amis

Update sandbox base AMIs.

util/jenkins/ansible-provision.sh

@@ -105,11 +105,11 @@ fi
 
 if [[ -z $ami ]]; then
   if [[ $server_type == "full_edx_installation" ]]; then
-    ami="ami-9d80dbf7"
+    ami="ami-b59cb5df"
   elif [[ $server_type == "ubuntu_12.04" || $server_type == "full_edx_installation_from_scratch" ]]; then
-    ami="ami-c15bebaa"
+    ami="ami-94be91fe"
   elif [[ $server_type == "ubuntu_14.04(experimental)" ]]; then
-    ami="ami-2dcf7b46"
+    ami="ami-35d6f95f"
   fi
 fi