Drop JDK6 and Scala 2.11 from build

.travis.yml

@@ -1,20 +1,10 @@
 language: scala
 
-# Needed for openjdk6
-dist: precise
-sudo: required
-addons:
-  hosts:
-    - localhost
-  hostname: localhost.local
-
 jdk:
-  - openjdk6
   - oraclejdk8
   - openjdk11
 
 scala:
-  - 2.11.12
   - 2.12.8
   - 2.13.0-RC1
 
@@ -38,26 +28,8 @@ matrix:
       env: SCALAJS_VERSION=0.6.27
     - jdk: openjdk11
       env: SCALAJS_VERSION=1.0.0-M7
-    - scala: 2.11.12
-      env: SCALAJS_VERSION=1.0.0-M7
-    - scala: 2.11.12
-      jdk: oraclejdk8
-    - scala: 2.11.12
-      jdk: openjdk11
-    - scala: 2.12.8
-      jdk: openjdk6
-    - scala: 2.13.0-RC1
-      jdk: openjdk6
-
-before_script:
-  - nvm install 8
-  - nvm use 8
 
 script: 
-  # work around https://github.com/travis-ci/travis-ci/issues/9713
-  - if [[ $JAVA_HOME = *java-6* ]]; then jdk_switcher use openjdk6; fi
-  - java -version
-  - node -v
   - admin/build.sh
 
 before_cache:

admin/build.sh

@@ -16,8 +16,7 @@ set -e
 # of the existing tag. Then a new tag can be created for that commit, e.g., `v1.2.3#2.13.0-M5`.
 # Everything after the `#` in the tag name is ignored.
 
-if [[ "$TRAVIS_JDK_VERSION" == "openjdk6" && "$TRAVIS_SCALA_VERSION" =~ 2\.11\..* \
-      || "$TRAVIS_JDK_VERSION" == "oraclejdk8" && "$TRAVIS_SCALA_VERSION" =~ 2\.1[23]\..* ]]; then
+if [[ "$TRAVIS_JDK_VERSION" == "oraclejdk8" && "$TRAVIS_SCALA_VERSION" =~ 2\.1[23]\..* ]]; then
   RELEASE_COMBO=true;
 fi
 
@@ -52,9 +51,4 @@ if [[ "$TRAVIS_TAG" =~ $tagPat ]]; then
   fi
 fi
 
-# Maven Central and Bintray are unreachable over HTTPS
-if [[ "$TRAVIS_JDK_VERSION" == "openjdk6" ]]; then
-  SBTOPTS="-Dsbt.override.build.repos=true -Dsbt.repository.config=./.sbtrepos"
-fi
-
-sbt $SBTOPTS "++$TRAVIS_SCALA_VERSION" "$publishVersion" "$projectPrefix/clean" "$projectPrefix/test" "$projectPrefix/publishLocal" "$publishTask"
+sbt "++$TRAVIS_SCALA_VERSION" "$publishVersion" "$projectPrefix/clean" "$projectPrefix/test" "$projectPrefix/publishLocal" "$publishTask"

build.sbt

@@ -1,7 +1,7 @@
 import sbtcrossproject.{crossProject, CrossType}
 import ScalaModulePlugin._
 
-crossScalaVersions in ThisBuild := List("2.12.8", "2.11.12", "2.13.0-RC1")
+crossScalaVersions in ThisBuild := List("2.12.8", "2.13.0-RC1")
 
 lazy val xml = crossProject(JSPlatform, JVMPlatform)
   .withoutSuffixFor(JVMPlatform)