Merge pull request #17 from UCL/staging

Staging
Merge branch 'master' of github.com:UCL/rsd-engineeringcourse

* 'master' of github.com:UCL/rsd-engineeringcourse:
Revert "Further deal with non-installation of package on production"

This reverts commit bf016732d78dd4b64a6d4af51a8bacff5708b5b4.
Revert "Tree is not installed in production; workaround"

This reverts commit 7c6ec48a4659dc7880721c512974d74d29ae37c6.

Conflicts:
	session04/03packaging.md
Revert "Deal with non-installation of greeter module on production"

This reverts commit 279fe3c9421356bb523d9919e129b8bd7ff2731e.