2.x: Upgrade to Gradle 4.2, remove nebula, custom rls (ReactiveX#5633)

.travis.yml

@@ -10,9 +10,9 @@ jdk:
 
 # prevent travis running gradle assemble; let the build script do it anyway
 install: true
-
+
+# running in container causes test failures and 2x-3x longer build, use standalone instances
 sudo: required
-# as per http://blog.travis-ci.com/2014-12-17-faster-builds-with-container-based-infrastructure/
 
 # script for build and release via Travis to Bintray
 script: gradle/buildViaTravis.sh

HEADER

@@ -0,0 +1,10 @@
+Copyright (c) 2016-present, RxJava Contributors.
+
+Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in
+compliance with the License. You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software distributed under the License is
+distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See
+the License for the specific language governing permissions and limitations under the License.