Rule for by-name right associative operators

Warnings for the issue presented in SI-1980:
https://issues.scala-lang.org/browse/SI-1980
Merge pull request #15 from Lewix/bynamerightassociative

Warn about by-name right associative operators
Rule for PackageObjectClasses

Warnings for the issue presented in SI-4344:
https://issues.scala-lang.org/browse/SI-4344
Merge pull request #16 from Lewix/packageobjectclasses

Rule for PackageObjectClasses
Bump Scala and Sbt versions.
More information during `sbt abide`.

* warn if no rules are applied
* show how many rules are applied
* log debug info about arguments passed to scalac.
Be more robust in case some types are missing on the class path in akka-specific rules.
Rule for nullary methods of Unit type.

Warns when a nullary method's result type is Unit.
Rule for avoiding size equals or not equals zero on Traversables
isInstanceOf and asInstanceOf ported from scapegoat as one abide rule
Merge pull request #17 from dragos/issue/sbt-more-info

More information during `sbt abide`.
Merge pull request #19 from dragos/issue/crash-akka-rule

Be more robust in case some types are missing on the class path
Using quasisquotes

Not entirely sure it made it better though
Big test split up in separate test cases
Merge pull request #20 from Lewix/nullaryunit

Rule for nullary methods of Unit type.
Merge pull request #24 from johanandren/rules/size-empty-nonempty

Rule for avoiding size equals or not equals zero on Traversables
Merge pull request #28 from johanandren/rules/as-instance-of

Warn on usage of isInstanceOf and asInstanceOf
Rule for inferences of Any

It uses tpt.original == null to check whether a TypeTree was inferred or not.
Merge pull request #30 from Lewix/inferany

Rule for inferences of Any
Rule for DelayedInitSelect

Implementation and tests are similar to scalac's.