Top rust-clippy issues

Disallow non-exhaustive matches

L-lint good-first-issue

Needs an Easter egg that makes a paperclip give you your lint messages.

`use_self` lint false positives

L-bug

Consistently naming lints

C-needs-discussion

Build failure with nightly 2018-05-21

cargo-clippy compile-errors on chrono 0.4.2

L-crash

crashes while checking dependency

L-crash

thread 'main' panicked at '`else return` is not possible'

lint: transmuting known null pointer to ref

L-lint T-AST good-first-issue hacktoberfest

Bikesheds to be done when RfCing clippy

C-needs-discussion M-question