Fix bugs for role validate servers

[ShPakvel]

There is syntactic typo-bug during validate_servers! invocation for role (wrong number of arguments).
It wasn't discovered because it has never met condition to run on. Role config wasn't correctly extracted for validation - another logical bug.
Both bugs fixed.

Also remove not used anymore accessories_on. Leftover from previous changes.

[djmb]

Hi @ShPakvel - is it possible to write a test for this condition?

[ShPakvel]

Hi @ShPakvel - is it possible to write a test for this condition?

Regarding to fix for syntax bug with wrong number of arguments

Existing tests already cover it. Here is example of test execution.
As I wrote, it wasn't caught by tests because of another logical bug interfered and prevented flow to validation.

$ ./bin/test test/configuration/role_test.rb

# ...

Error:
ConfigurationRoleTest#test_cmd:
ArgumentError: wrong number of arguments (given 2, expected 1)
    lib/kamal/configuration/validator.rb:110:in `validate_servers!'
    lib/kamal/configuration/validator/role.rb:6:in `validate!'
    lib/kamal/configuration/validation.rb:21:in `validate!'
    lib/kamal/configuration/role.rb:12:in `initialize'

# ...

bin/test /home/shpakvel/projects/github/kamal/test/configuration/role_test.rb:32

Finished in 0.069962s, 285.8696 runs/s, 57.1739 assertions/s.
20 runs, 4 assertions, 0 failures, 18 errors, 0 skips

And tests are passed when code is corrected.

$ ./bin/test test/configuration/role_test.rb
Run options: --seed 49549

# Running:

....................

Finished in 0.190348s, 105.0708 runs/s, 262.6770 assertions/s.
20 runs, 50 assertions, 0 failures, 0 errors, 0 skips

Regarding logical bug.

• It looks like simple overlooked difference between specializations and role_config. And after this change, difference is clearly stated in code logic.
• And right now it is private part of class.

Which leads us to choose between these ways to proceed:

• A - to consider this part as internal (private) that shouldn't be tested.
• B - to make specializations and role_config methods public, and right tests on what they should return.

@djmb, Let me know which way you prefer A or B. If it is B, I will proceed with changes and tests creation.

[djmb]

Ok, that makes sense, thanks! All good to merge as it is then