Correcting .travis.yml as discussed

.travis.yml

@@ -1,18 +1,9 @@
 language: java
 sudo: false
+install: mvn dependency:go-offline
 script: mvn -Pdev verify
 jdk:
   - oraclejdk8
-  - openjdk8
 env:
   global:
-    - JAVA_OPTS="-Xmx1024M -Xms512M"
-notifications:
-  irc:
-    channels:
-      - "irc.freenode.org#jena"
-    on_success: change
-    on_failure: always
-    template:
-      - "%{repository} (%{branch}:%{commit} by %{author}): %{message} (%{build_url})"
-    skip_join: true
+- JAVA_OPTS="-Xmx3072M -Xms512M -XX:+UseG1GC"