Wikimedia: Add integration test for Wikimedia preset

To help catch potential regressions against the standard.
Correct deal with exclusion and extensions

Fixes #488
Add tests for checker#checkFile methods
Exclude colon from binary rule of yandex preset

/cc @lemmy-
Prepare for version 1.5.7
1.5.7
Remove dev only line in readme at publish command

Also break publish commands on helper modules

Fixes #470
Make lints happy

Fix issues founded by JSCS and JSHint checks
Correct publish helper name

Per @mikesherov review
Remove another needless line from the doc
Build: avoid using `prepublish` because it runs on `npm install`.

Cleans up the maintenance guide as well so it reads slightly better.

Fixes #493
Errors: include which rule triggered the error in the error output
requireTrailingComma: Avoids false positives from non object/array literal definitions. 

Fixes #368
Tests: return promises rather than use `done()` callbacks.

Fixes #500
requireAlignedObjectValues: undocument 'skipWith' in favor of 'ignore'.

'skipWith' is an awkward way of saying 'ignore', which is the standardized
way to specify not doing something. The rule itself has also been improved
for clarity.