revert script back to target latest

Author: williexu

scripts/update.sh

@@ -8,7 +8,7 @@ cd $workdir
 if [ ! -d venv ]; then
     python -m virtualenv venv
     . venv/bin/activate
-    pip install azure-storage-blob==1.2.0rc1 azure-storage-file==1.2.0rc1 azure-storage-queue==1.2.0rc1 azure-storage-common==1.2.0rc1
+    pip install azure-storage-blob azure-storage-file azure-storage-queue azure-storage-common
 fi
 
 ver=$(find venv -name '_constants.py' | grep blob | xargs grep 'X_MS_VERSION')