added coveralls badge to README.adoc
added coveralls badge to README.adoc
NicolasGeraud/asciidoctor-maven-plugin,asciidoctor/asciidoctor-maven-plugin,asciidoctor/asciidoctor-maven-plugin,asciidoctor/asciidoctor-maven-plugin,abelsromero/asciidoctor-maven-plugin,abelsromero/asciidoctor-maven-plugin,abelsromero/asciidoctor-maven-plugin