Allow version passed to update_version.sh to start with "version-" prefix

This allows you to copy-paste a tag and edit it for the new version.

update_version.sh

@@ -1,13 +1,15 @@
 #!/bin/bash
 
-if [ -z "$1" ]; then
+VERSION="${1/version-}"
+
+if [ -z "$VERSION" ]; then
     echo "Usage: $0 new-version" >&2
     exit 1
 fi
 
-BL_INFO_VER=$(echo "$1" | sed 's/\./, /g')
+BL_INFO_VER=$(echo "$VERSION" | sed 's/\./, /g')
 
-sed "s/version='[^']*'/version='$1'/" -i setup.py
+sed "s/version='[^']*'/version='$VERSION'/" -i setup.py
 sed "s/'version': ([^)]*)/'version': ($BL_INFO_VER)/" -i blender_cloud/__init__.py
 
 git diff