Updated tests, improved display
Merge pull request #8 from AltGr/up-tests

Updated tests, improved display
Made it easier to add new tests
They only need to be registered in OpamRt
Merge pull request #9 from AltGr/simplify-adding-tests

Made it easier to add new tests
Added reinstall test, checking order and not-available-anymore packages.
Merge pull request #10 from AltGr/reinstall-test

Added reinstall test, checking order and not-available-anymore packages.
Add @AltGr as main author
Simplify (and fix) the Makefile
Start fixing some some tests following the last branch merge.
Add 'opam-rt test' to init+run a test and improve the display in case of errrors.

Simplify the Makefile again.
Start testing some state invariants