GROOVY-6929: Fix NPE with map constructor calls and setter only
Objecct -> Object

Sorry, my mistake.
Merge pull request #479 from yukoba/patch-3

Objecct -> Object
Documentation about running one unit test

It is written here
https://github.com/groovy/groovy-core/blob/master/gradle/test.gradle#L66
but I think it is worth writing it on README.adoc.
Merge pull request #480 from yukoba/patch-4

Documentation about running one unit test
GROOVY-6933: Add swap() to List and array.
Collections.swap() returns nothing, but this method returns this object.
First bits of work around quality builds:
   * re-enabled checkstyle
   * generate HTML report
   * CodeNarc, Cobertura disabled
Upgrade to Asciidoctor Gradle plugin 0.7.3
Merge pull request #481 from yukoba/Swap

GROOVY-6933: Add swap() to List and array
GROOVY-6928: Support all the Java 6 classes at createSimilarCollection() and createSimilarMap()