Fix all custom rules not being applied when any rule is configured incorrectly

[JamieEdge]

Addresses #1586 by adding handling.

[SwiftLintBot]

	1 Warning
⚠️	Make sure that the docs are updated by running the Generate docs scheme.

	12 Messages
📖	Linting Aerial with this PR took 0.36s vs 0.34s on master (5% slower)
📖	Linting Alamofire with this PR took 2.24s vs 2.27s on master (1% faster)
📖	Linting Firefox with this PR took 9.81s vs 9.82s on master (0% faster)
📖	Linting Kickstarter with this PR took 13.96s vs 14.04s on master (0% faster)
📖	Linting Moya with this PR took 0.63s vs 0.64s on master (1% faster)
📖	Linting Nimble with this PR took 1.26s vs 1.29s on master (2% faster)
📖	Linting Quick with this PR took 0.42s vs 0.42s on master (0% slower)
📖	Linting Realm with this PR took 1.96s vs 1.98s on master (1% faster)
📖	Linting SourceKitten with this PR took 0.83s vs 0.85s on master (2% faster)
📖	Linting Sourcery with this PR took 2.66s vs 2.7s on master (1% faster)
📖	Linting Swift with this PR took 9.38s vs 9.4s on master (0% faster)
📖	Linting WordPress with this PR took 9.27s vs 9.46s on master (2% faster)

Generated by 🚫 Danger

[codecov-io]

Codecov Report

Merging #1681 into master will decrease coverage by 0.02%.
The diff coverage is 57.14%.

@@            Coverage Diff             @@
##           master    #1681      +/-   ##
==========================================
- Coverage   87.35%   87.33%   -0.03%     
==========================================
  Files         201      201              
  Lines       10003    10009       +6     
==========================================
+ Hits         8738     8741       +3     
- Misses       1265     1268       +3

Impacted Files	Coverage Δ
Source/SwiftLintFramework/Rules/CustomRules.swift	93.1% <57.14%> (-4.98%)	⬇️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update c7decb7...bc7c81c. Read the comment docs.

[marcelofabri]

This looks great 🎉

Can you add a test to make sure we don't break it in the future?

[marcelofabri]

Merged in #1683. Thanks @JamieEdge 🎉