Update version for 2.4.1 release

Update Java source compatibility to Java 8
Update Travis CI build configuration

.travis.yml

@@ -5,25 +5,25 @@ android:
     - platform-tools
     - tools
     - tools #not a typo. Needed for SDK update
-    - build-tools-27.0.3
+    - build-tools-29.0.0
 
     # The SDK version used to compile your project
-    - android-27
+    - android-29
 
     # Additional components
     - extra-android-support
     - extra-google-google_play_services
     - extra-google-m2repository
     - extra-android-m2repository
-    - addon-google_apis-google-26
+    - addon-google_apis-google-29
 
     # Specify at least one system image,
     # if you need to run emulator(s) during your tests
     #- sys-img-armeabi-v7a-android-23
 
 # XXX: Temporary workaround. Remove once fixed
 before_install:
-    - yes | sdkmanager "platforms;android-27"
+    - yes | sdkmanager "platforms;android-29"
 
 # Emulator Management: Create, Start and Wait
 # Re-enable this when we figure out how to reliably build on Travis

app/build.gradle

@@ -5,8 +5,8 @@ apply plugin: 'io.fabric'
 
 def versionMajor = 2
 def versionMinor = 4
-def versionPatch = 0
-def versionBuild = 3
+def versionPatch = 1
+def versionBuild = 0
 
 static def buildTime() {
     def df = new SimpleDateFormat("yyyyMMdd HH:mm 'UTC'")