Allow extraction of bz2 files during build process
Allow extraction of bz2 files during build process

# The build process seems to need to download PhantomJS, and it does so via
# a bz2 file which must be extracted using the bzip2 package!

ucam-cl-dtg/isaac-app,ucam-cl-dtg/isaac-app,ucam-cl-dtg/isaac-app,ucam-cl-dtg/isaac-app