refactor: renames functions that assert things so they reflect that

[sverweij]

Description

• in the cli renames assertion that checks whether the node environment is suitable
• in the main 'option' check renames functions that assert whether the options are valid
• in the main 'rule-set' renames functions that assert whether the rule set is valid

Motivation and Context

A lot of the assertions dependency-cruiser makes before starting were called 'validate' - which is not as clear/ descriptive of the actual functionality of the functions as 'assert' is. Renaming

How Has This Been Tested?

• green ci
• updated automated non-regression tests

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• Documentation only change
• Refactor (non-breaking change which fixes an issue without changing functionality)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• 📖

  • My change doesn't require a documentation update, or ...
  • it does and I have updated it

• ⚖️

  • The contribution will be subject to The MIT license, and I'm OK with that.
  • The contribution is my own original work.
  • I am ok with the stuff in CONTRIBUTING.md.

[codeclimate]

Code Climate has analyzed commit 5f941e9 and detected 0 issues on this pull request.

View more on Code Climate.