New configurable settings: encryption for audited_changes & filtering encrypted attrs

[sriddbs]

Closes #690

• Add new configurable vars:
  • encrypt_audited_changes default to false
  • filter_encrypted_attributes default to true

[sriddbs]

@danielmorrison please review and let me if the proposed config in the PR is good, also I wonder why some of the specs are failing 🤔

[sriddbs]

Looking good to me. Test errors are something strange with coverage? Doesn't make sense offhand.

I had the same errors with spec/audited/audit_spec, rspec clearly showed me the errors locally and I could fix it

for this it just runs fine

rspec spec/audited/auditor_spec.rb
Created database ':memory:'
............................................................................................................*.....*........................

Pending: (Failures listed here are expected and do not affect your suite's status)

  1) Audited::Auditor without auditing should be thread safe using a #without_auditing block
     # No reason given
     # ./spec/audited/auditor_spec.rb:996

  2) Audited::Auditor with auditing should be thread safe using a #with_auditing block
     # No reason given
     # ./spec/audited/auditor_spec.rb:1077

[sriddbs]

@danielmorrison if this PR looks good, please merge?