Improve no-array-mutation

[RebeccaStevens]

Fixes: #88

Added option ignore-mutation-following-accessor that allows for mutating methods to be using directly after an accessor method in a chain.

For example:

const sorted = ["foo", "bar"].slice().sort((a, b) => a.localeCompare(b));

[coveralls]

Coverage decreased (-0.4%) to 98.84% when pulling b6f26e3 on RebeccaStevens:issue-88 into 7e27e6f on jonaskello:master.

[jonaskello]

Nice work :-)

[jonaskello]

Released in 4.7.0