Show decimals for Metrics/AbcSize:Max if given in config

The reporting of the offense should include a decimal
if set like that in a configuration file.

And increase the number of significant digits reported
for the size. Otherwise we get output such as [44/44]
when the size is just above 44.

Allowing a little bit of duplication makes the specs
more readable than with the method registers_offense.
Merge pull request #1392 from jonas054/fix_abc_size_decimal

Show decimals for Metrics/AbcSize:Max if given in config
[Fix #1181] New cop StringLiteralsInInterpolation
Extract common code into mixins
Merge pull request #1393 from jonas054/1181_quotes_in_interpolation

Check quotes in interpolation
Better coverage for NonNilCheck
Refactor NonNilCheck specs
Refactor NonNilCheck
Output two different messages from NonNilCheck
Update the class documentation for CollectionMethods
[Fix #1084] Disable CollectionMethods by default

The cop yields false positives in some scenarios, so it's better
to have it disabled by default.

This also fixes #1334.
Remove an extra space
Change name of the module OnMethod to OnMethodDef

To indicate clearly that it's about method definition
nodes, not method call nodes.
Merge pull request #1394 from jonas054/work_on_non_nil_check

NonNilCheck improvements
[Fix #872] Make IndentationWidth configurable

Default is 2 spaces.
Merge pull request #1395 from jonas054/configurable_indentation_width

[Fix #872] Make IndentationWidth configurable
[Fix #1396] Include .opal files by default
[Fix #771] Three new cops to replace Style/EmptyLinesAroundBody

In order to make it possible to configure where we
want empty lines and where we don't want them, the
EmptyLinesAroundBody cop is removed and replaced
by three new cops, EmptyLinesAroundMethodBody,
EmptyLinesAroundClassBody, and
EmptyLinesAroundModuleBody. The last two can be
configured to require or disallow empty lines
around the body.
More detailed messages about empty lines
Merge pull request #1399 from jonas054/771_configurable_empty_lines

Configurable empty lines