Update dependency tslint to ~5.19.0

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
tslint (source)	devDependencies	minor	~5.18.0 -> ~5.19.0

---

Release Notes

palantir/tslint

v5.19.0

Compare Source

• [bugfix] relax promise-function-async for short parenthesized arrow functions (#​4765)
• [bugfix] fix no-async-without-await false positive for abstract methods (#​4782)
• [bugfix] fix strict-comparison false positive for null and undefined literals (#​4786)
• [bugfix] improve no-angle-bracket-type-assertion autofix semantics with more parentheses (#​4823)
• [enhancement] add BigInt support to restrict-plus-operands rule (#​4814)
• [enhancement]await-promise now supports new TypeScript 3.6 AST API symbols for async iterators (#​4800)
• [new-rule-option] check-strings and check-regex options for max-line-length rule (#​4798)
• [new-rule-option] variable-declaration-ignore-function option for typedef rule (#​4769)
• [new-rule-option] ignore-blank-lines option for object-literal-sort-keys rule (#​4808)
• [new-rule]no-for-in (#​4747)
• [new-rule]no-invalid-void (#​4736)
• [new-rule]strict-string-expressions reports errors on type coercions found in string expressions (#​4807)
• [new-rule]'no-promise-as-boolean' (#​4790)
• [docs] link to OSS fellowship medium post in README (#​4821)

Thanks to our contributors!

• Josh Pike
• Tanmoy Bhowmik
• Michael Withagen
• Evgeniy Timokhov
• Vitalij Krotov
• Josh Goldberg
• Veda
• Guido
• Robert Fink
• Max Sysoev

---

Renovate configuration

📅 Schedule: "after 4:00am every 2nd week of the month" in timezone UTC.

🚦 Automerge: Enabled.

♻️ Rebasing: Whenever PR becomes conflicted, or if you modify the PR title to begin with "rebase!".

🔕 Ignore: Close this PR and you won't be reminded about this update again.

---

• If you want to rebase/retry this PR, check this box

---

This PR has been generated by Renovate Bot. View repository job log here.