Update tslint to the latest version 🚀

[greenkeeper]

Version 5.6.0 of tslint just got published.

Dependency	tslint
Current Version	5.5.0
Type	devDependency

The version 5.6.0 is not covered by your current version range.

Without accepting this pull request your project will work just like it did before. There might be a bunch of new features, fixes and perf improvements that the maintainers worked on for you though.

I recommend you look into these changes and try to get onto the latest version of tslint.
Given that you have a decent test suite, a passing build is a strong indicator that you can take advantage of these changes by merging the proposed change into your project. Otherwise this branch is a great starting point for you to work on the update.

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Release Notes

v5.6.0

🎉 New rules, options, and fixers

• [new-rule] no-duplicate-imports (#3075)
• [new-rule] no-submodule-imports (#3091)
• [new-rule] space-within-parens (#2959)
• [new-fixer] member-access (#2969)
• [new-fixer] no-null-keyword: fix x == null to x == undefined (#2802)
• [new-rule-option] no-shadowed-variable let's you optionally ignore certain kinds of declarations (#3030)
• [new-rule-option] prefer-conditional-expression adds check-else-if (#2963)

🛠 Bugfixes & enhancements

• [bugfix] array-type: consider this to be simple type (#2982)
• [bugfix] await-promise accepts not only union types but also intersection types with Promise-like types (#2987)
• [bugfix] callable-types: don't remove export modifier of interfaces (#2962)
• [bugfix] completed-docs: Only checks variables at the file-level. (#2950)
• [bugfix] completed-docs: Uses correct visibility of variables. (#2950)
• [bugfix] no-floating-promises: recognize rejection handler passed as second argument to promise.then() (#3048)
• [bugfix] no-shadowed-variable don't warn for shadowed type parameter on static class members (#3030)
• [bugfix] no-shadowed-variable fixed false positive with key name in index signature (#3030)
• [bugfix] no-shadowed-variable fixed false positive with parameter inside function decorator (#3030)
• [bugfix] no-unsafe-any: allow truthyness and falsyness checks (#3008)
• [bugfix] no-unused-variable fixed crash when using destructuring (#3058)
• [bugfix] one-line correctly handles multiline type parameters (#3004)
• [bugfix] prefer-for-of fixed false positives when array is modified, e.g. arr[i]++ (#3044)
• [bugfix] prefer-object-spread adds parens when fixing arrow function return (#3026)
• [bugfix] prefer-object-spread permit functions as first argument to Object.assign (#3098)
• [bugfix] space-before-function-paren Handle default exports of functions without names like anonymous functions (fixes #3040) (#3053)
• [bugfix] Fixed an issue where, at runtime, the module ./test/parse could not be located due after consumers had run yarn clean (#3072)
• [enhancement] no-null-keyword allows strict comparison (#2802)
• [enhancement] no-switch-case-fall-through matches // falls through comments case insensitive and allows trailing text (#2983)
• [enhancement] ordered-imports: support importEqualsDeclaration (#3102)
• [enhancement] Added NaN and (+/-)Infinity as numbers to no-inferrable-types (#2885)
• [enhancement] Improved CLI error message when no filenames are specified (#3066)
• [rule-change] prefer-conditional-expression: ignore if-else-if by default. Use the new "check-else-if" option to check nested if statements (#2963)

Thanks to our contributors!

• Klaus Meinhardt
• Julian Verdurmen
• Alexandre Alonso
• Josh Goldberg
• ksvitkovsky
• Daisuke Yokomoto
• Andrii Dieiev
• Florent Suc
• Jason Killian
• Amin Pakseresht
• reduckted
• vilicvane
• Russell Briggs
• Andy Hanson
• Leo Liang
• Dan Homola
• BehindTheMath
• David Golightly
• aervin
• Daniel Kucal
• Ika
• Chris Barr

Not sure how things should work exactly?

There is a collection of frequently asked questions and of course you may always ask my humans.

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Your Greenkeeper Bot 🌴