code: move commands to it's subcommand

[jcs090218]

1. Move all test commands to live under command eask test

PS C:\Users\XXX\path\to\project> eask test
test <type>

run test

Commands:
  test buttercup [files..]    run buttercup tests
  test ert-runner [files..]   run ert tests using ert-runner
  test ert [files..]          run ert tests

Options:
...

2. Move all lint commands to live under command eask lint

PS C:\Users\XXX\path\to\project> eask lint
lint <type>

run linter

Commands:
  lint checkdoc [files..]   run checkdoc
  lint declare [files..]    run check-declare
  lint elint [files..]      run elint
  lint elsa [files..]       run elsa
  lint indent [files..]     lint the package using indent-lint
  lint package [files..]    lint the package using package-lint
  lint regexps [files..]    run relint
Options:
...

---

✔ Now we do

$ eask test ert [...]
$ eask lint elsa [...]

❌ Instead

$ eask ert [...]
$ eask elsa [...]