Added a runtime datastructure called `test` that stores the following:
  - the description
  - tags
  - a lambda
This, in addition to the addition of adding `tags` to the env, lays the groundwork for having specs with tags. This datastructure could also facilitate running before-alls and after-alls.
Merge branch 'add-tags' of github.com:nahiluhmot/specl into add-tags

Conflicts:
	src/package.lisp