Issue #118 : Require minimum JDK 1.7
Issue #118 : Require minimum JDK 1.7

- Fixed JAVA_HOME (see https://discuss.circleci.com/t/using-openjdk-8/68)
- Show Maven and JDK version when building

marcelmay/greenmail,greenmail-mail-test/greenmail,chriswhite199/greenmail,marcelmay/greenmail,greenmail-mail-test/greenmail,marcelmay/greenmail,buildscientist/greenmail,buildscientist/greenmail,buildscientist/greenmail,buildscientist/greenmail,greenmail-mail-test/greenmail,marcelmay/greenmail,chriswhite199/greenmail,chriswhite199/greenmail,marcelmay/greenmail,chriswhite199/greenmail,buildscientist/greenmail,chriswhite199/greenmail