Missing CLI tests

[mohammadfawaz]

There are a few commands that are not tested in our CLI integration testing. Keeping track of a list here so we can address them one by one:

1. leo account
2. leo add
3. leo clean
4. leo debug (though we might be deprecating that for some time)
5. leo devnet and leo devnode
6. leo new
7. leo remove
8. leo run
9. leo synthesize
10. leo update
11. leo upgrade