Delete travis-ci support

.travis.yml

@@ -1,30 +0,0 @@
-language: android
-jdk: oraclejdk8
-dist: trusty
-
-android:
-  components:
-    - tools
-    - platform-tools
-    - build-tools-28.0.3
-    - android-29
-
-before_script:
-  - export NDK_VERSION=r19c
-  - curl -L https://dl.google.com/android/repository/android-ndk-${NDK_VERSION}-linux-x86_64.zip -O
-  - unzip -q android-ndk-${NDK_VERSION}-linux-x86_64.zip
-  - export ANDROID_NDK_HOME=`pwd`/android-ndk-${NDK_VERSION}
-
-before_cache:
-  - rm -f  $HOME/.gradle/caches/modules-2/modules-2.lock
-  - rm -fr $HOME/.gradle/caches/*/plugin-resolution/
-cache:
-  directories:
-    - $HOME/.gradle/caches/
-    - $HOME/.gradle/wrapper/
-
-script:
-  - ./gradlew assembleDebug
-
-notifications:
-  email: false