Fix a decode error with BitBucket server

[pepix]

Issue

I faced a decode error when I run $ danger-swift pr <pr_url> for a certain pull request in GitBucket Server.
As my investigation, it seems they don't return public field if that repository is forked by someone.
After I made it optional, it works.

ERROR: Failed to parse JSON: keyNotFound(CodingKeys(stringValue: "public", intValue: nil), Swift.DecodingError.Context(codingPath: [CodingKeys(stringValue: "danger", intValue: nil), CodingKeys(stringValue: "bitbucket_server", intValue: nil), CodingKeys(stringValue: "pr", intValue: nil), CodingKeys(stringValue: "fromRef", intValue: nil), CodingKeys(stringValue: "repository", intValue: nil), CodingKeys(stringValue: "project", intValue: nil)], debugDescription: "No value associated with key CodingKeys(stringValue: "public", intValue: nil) ("public").", underlyingError: nil))

ERROR: Dangerfile eval failed at Dangerfile.swift
ERROR: Could not get the results JSON file at /var/folders/__/clhhlm6d5fg7__h0syj9vmtw0000gv/T/danger-response.json

[f-meloni]

Thank you!
Could you please add a test for this? (not a blocker)

[pepix]

I can't find why CI failed though got no errors locally..

[pepix]

Posted issue since I found an issue on CI pipeline #556

[f-meloni]

I have made few changes to reduce the noise made from swiftlint and swiftformat, I will merge this so that it can make it in the release and work on swiftlint as a separated issue.