Enable vagrant-cachier and check if vagrant-berkshelf is available

Add two changes from the main Vagrantfile also to the Vagrantfiles
in ds-build and split.

* Id3aeaa16e062f764412bd6c5fd9460b5867333a9 (vagrant-cachier)
* Ie615cf81be40b8395d8e7672e59407cc4925b410 (vagrant-berkshelf)

Change-Id: I2309db433c547736732217ffcd1e1f440d1684ab
Merge "Enable vagrant-cachier and check if vagrant-berkshelf is available"