[new-formatter] TAP formatter

[LKay]

PR checklist

• Addresses an existing issue: #0000
• New feature, bugfix, or enhancement
  • Includes tests
• Documentation update

Overview of change:

Adds new TAP formatter for failures output. Can be used with any TAP reporter

CHANGELOG.md entry:

• [enhancement] New TAP formatter

[palantirtech]

Thanks for your interest in palantir/tslint, @LKay! Before we can accept your pull request, you need to sign our contributor license agreement - just visit https://cla.palantir.com/ and follow the instructions. Once you sign, I'll automatically update this pull request.

[ajafff]

no need to modify the changelog. that is done when the next version is released to avoid merge conflicts.
Just add [new-formatter] TAP formatter to the opening post of the PR.

[ajafff]

s/2013/2017/

[ajafff]

Just a suggestion: use multiline template strings and Utils.dedent

            return Utils.dedent`
                not ok ${i + 1} - ${failureMessage}
                  ---
                  message : ${failureMessage}
                  severity: ${failureSeverity}
                  data:
                    ruleName: ${ruleName}
                    fileName: ${fileName}
                    line: ${lineAndCharacter.line}
                    character: ${lineAndCharacter.character}
                    failureString: ${failureString}
                    rawLines: ${failureRaw}
                  ...`;

[nchen63]

@LKay thanks!