v0.19.0

Features:

• new rule: no-useless-try-catch
• no-useless-predicate: detect comparing a literal type with itself
• no-useless-predicate: detect redundant uses of key in obj where key is known to always be present in obj

Bugfixes:

• no-useless-predicate: treat property access on index signatures as potentially undefined
• no-useless-predicate: don't report expressions as "always truthy" without strictNullChecks
• no-useless-predicate: avoid nested finding by reporting only the innermost finding