Sets VDI to be stored in same dir as Vagrantfile

The VagrantfilePath variable points directly to the same path that the
Vagrantfile lives within, therefore there is no further need to ensure `..`
appears in the `file_to_disk` variable.
Re-run librarian-puppet
Rename `size` to `secondHDDSize`

The top-scope variable, `size`, is too generic to include at the top level. It
does not accurately refer to anything specific. This commit amends the name of
the variable to `secondHDDSize` and amends anything using it to match.
Remove whitespace