vagrant_lock was created in order to prevent parallel execution of two 'Vagrant up' operations in parallel. Previously it was necessary due to Vagrant internal Chef issue. Now several bugs in Vagrant are fixed and MDBCI uses own Chef to provision nodes for builds and tests. There is no need to wait for previous Vagrant run finished, removing all waiting from all scripts.
'rm vagrant_lock is still present to remove locks created by previous versions of build and test scripts-
