workaround M1

I think I screwed up the M1 publishing, since it's missing sbt-launch.jar that sbt extra needs.

.travis.yml

@@ -1,10 +1,21 @@
 dist: trusty
 group: stable
 
-language: scala
+language: ruby
 jdk: oraclejdk8
 
-script: sbt scripted
+before_script:
+ - export JVM_OPTS="-Dfile.encoding=UTF-8 -Xmx1G -Xms1G -server -XX:ReservedCodeCacheSize=128M"
+
+script: /usr/bin/sbt scripted
+
+addons:
+  apt:
+    sources:
+      - sourceline: 'deb https://dl.bintray.com/sbt/debian /'
+      - key_url: 'https://bintray.com/user/downloadSubjectPublicKey?username=sbt'
+    packages:
+      - sbt=1.1.6
 
 # Undo _JAVA_OPTIONS environment variable
 before_script: