### New features

* [#1348](https://github.com/rubocop/rubocop/issues/1348): New cop `ElseAlignment` checks alignment of `else` and `elsif` keywords. ([@jonas054][])
* [#1321](https://github.com/rubocop/rubocop/issues/1321): New cop `MultilineOperationIndentation` checks indentation/alignment of binary operations if they span more than one line. ([@jonas054][])
* [#1077](https://github.com/rubocop/rubocop/issues/1077): New cop `Metrics/AbcSize` checks the ABC metric, based on assignments, branches, and conditions. ([@jonas054][], [@jfelchner][])
* [#1352](https://github.com/rubocop/rubocop/issues/1352): `WordArray` is now configurable with the `WordRegex` option. ([@bquorning][])
* [#1181](https://github.com/rubocop/rubocop/issues/1181): New cop `Style/StringLiteralsInInterpolation` checks quotes inside interpolated expressions in strings. ([@jonas054][])
* [#872](https://github.com/rubocop/rubocop/issues/872): `Style/IndentationWidth` is now configurable with the `Width` option. ([@jonas054][])
* [#1396](https://github.com/rubocop/rubocop/issues/1396): Include `.opal` files by default. ([@bbatsov][])
* [#771](https://github.com/rubocop/rubocop/issues/771): Three new `Style` cops, `EmptyLinesAroundMethodBody` , `EmptyLinesAroundClassBody` , and `EmptyLinesAroundModuleBody` replace the `EmptyLinesAroundBody` cop. ([@jonas054][])

### Changes

* [#1084](https://github.com/rubocop/rubocop/issues/1084): Disabled `Style/CollectionMethods` by default. ([@bbatsov][])

### Bugs fixed

* `AlignHash` no longer skips multiline hashes that contain some elements on the same line. ([@mvz][])
* [#1349](https://github.com/rubocop/rubocop/issues/1349): `BracesAroundHashParameters` no longer cleans up whitespace in autocorrect, as these extra corrections are likely to interfere with other cops' corrections. ([@jonas054][])
* [#1350](https://github.com/rubocop/rubocop/issues/1350): Guard against `Blocks` cop introducing syntax errors in auto-correct. ([@jonas054][])
* [#1374](https://github.com/rubocop/rubocop/issues/1374): To eliminate interference, auto-correction is now done by one cop at a time, with saving and re-parsing in between. ([@jonas054][])
* [#1388](https://github.com/rubocop/rubocop/issues/1388): Fix a false positive in `FormatString`. ([@bbatsov][])
* [#1389](https://github.com/rubocop/rubocop/issues/1389): Make `--out` to create parent directories. ([@yous][])
* Refine HTML formatter. ([@yujinakayama][])
* [#1410](https://github.com/rubocop/rubocop/issues/1410): Handle specially Java primitive type references in `ColonMethodCall`. ([@bbatsov][])

[@bbatsov]: https://github.com/bbatsov
[@jonas054]: https://github.com/jonas054
[@yujinakayama]: https://github.com/yujinakayama
[@dblock]: https://github.com/dblock
[@nevir]: https://github.com/nevir
[@daviddavis]: https://github.com/daviddavis
[@sds]: https://github.com/sds
[@fancyremarker]: https://github.com/fancyremarker
[@sinisterchipmunk]: https://github.com/sinisterchipmunk
[@vonTronje]: https://github.com/vonTronje
[@agrimm]: https://github.com/agrimm
[@pmenglund]: https://github.com/pmenglund
[@chulkilee]: https://github.com/chulkilee
[@codez]: https://github.com/codez
[@emou]: https://github.com/emou
[@skanev]: http://github.com/skanev
[@claco]: http://github.com/claco
[@rifraf]: http://github.com/rifraf
[@scottmatthewman]: https://github.com/scottmatthewman
[@ma2gedev]: http://github.com/ma2gedev
[@jeremyolliver]: https://github.com/jeremyolliver
[@hannestyden]: https://github.com/hannestyden
[@geniou]: https://github.com/geniou
[@jkogara]: https://github.com/jkogara
[@tmorris-fiksu]: https://github.com/tmorris-fiksu
[@mockdeep]: https://github.com/mockdeep
[@hiroponz]: https://github.com/hiroponz
[@tamird]: https://github.com/tamird
[@fshowalter]: https://github.com/fshowalter
[@cschramm]: https://github.com/cschramm
[@bquorning]: https://github.com/bquorning
[@bcobb]: https://github.com/bcobb
[@irrationalfab]: https://github.com/irrationalfab
[@tommeier]: https://github.com/tommeier
[@sfeldon]: https://github.com/sfeldon
[@biinari]: https://github.com/biinari
[@barunio]: https://github.com/barunio
[@molawson]: https://github.com/molawson
[@wndhydrnt]: https://github.com/wndhydrnt
[@ggilder]: https://github.com/ggilder
[@salbertson]: https://github.com/salbertson
[@camilleldn]: https://github.com/camilleldn
[@mcls]: https://github.com/mcls
[@yous]: https://github.com/yous
[@vrthra]: https://github.com/vrthra
[@SkuliOskarsson]: https://github.com/SkuliOskarsson
[@jspanjers]: https://github.com/jspanjers
[@sch1zo]: https://github.com/sch1zo
[@smangelsdorf]: https://github.com/smangelsdorf
[@mvz]: https://github.com/mvz
[@jfelchner]: https://github.com/jfelchner
