* get rid of invoke_tests imports
* add sudo
* change path to /usr/bin/invoke_tests
* create /usr/local/bin dir
* remove local variables
* fix group owner
* set default 775 perm
* delete invoke_tests symlink
* set -e and fix all the scripts
* add source utils to finalize_vm script
* change xcode version in postbuild script
* fix for softwareupdates and for xcode version