bug(cz_conventional_commits): cz check's schema_pattern is inconsistent with conventional commits spec

[shifqu]

Description

The schema_pattern used in ConventionalCommitsCz allows for a ! before the scope, while the spec states

13. If included in the type/scope prefix, breaking changes MUST be indicated by a ! immediately before the :.

Steps to reproduce

1. Run cz -n cz_conventional_commits check -m "feat!(scope): message"
2. Observe the (wrongly) successful validation
3. Run cz -n cz_conventional_commits check -m "feat(scope)!: message"
4. Observe the (wrongly) failed validation

Current behavior

• Command in 1) validates successfully
• Command in 3) fails validations

Desired behavior

• Command in 1) to fail validation (as the ! is not right before the :.)
• Command in 3) to validate successfully (as it aligns with the conventional commits spec)

Environment

• commitizen version: 2.17.4
• python version: 3.8.8
• operating system: Darwin (macOS 11.2.3)

[shifqu]

@woile I can take a stab at it, if you like. I feel like the change is minor.

[woile]

Of course, go ahead.