doc+build: Prepare release 0.2.1

This commit also fixes build issue on Travis-CI

Change-Id: Ic48ec8ca5b196cd02215622284656aca78582aa0
diff --git a/.travis.yml b/.travis.yml
index c89383a..08520ae 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -7,12 +7,17 @@
     on_success: always
     on_failure: always
 env:
- - NDK_BUILD_ABI=arm64-v8a
- - NDK_BUILD_ABI=armeabi
- - NDK_BUILD_ABI=armeabi-v7a
- - NDK_BUILD_ABI=mips
- - NDK_BUILD_ABI=x86
- - NDK_BUILD_ABI=x86_64
+  global:
+    - TERM=dumb
+    - GRADLE_OPTS="-Xmx768m -Xms256m -Xss1m"
+    - NDK_BUILD_PARALLEL=1
+  matrix:
+    - NDK_BUILD_ABI=arm64-v8a
+    - NDK_BUILD_ABI=armeabi
+    - NDK_BUILD_ABI=armeabi-v7a
+    - NDK_BUILD_ABI=mips
+    - NDK_BUILD_ABI=x86
+    - NDK_BUILD_ABI=x86_64
 addons:
   apt:
     packages:
@@ -35,4 +40,4 @@
   - travis_retry .jenkins.d/10-get-ndk.sh
 script:
   - git submodule update --init --recursive
-  - GRADLE_OPTS="-Xmx768m -Xms256m -Xss1m" NDK_BUILD_PARALLEL=1 ./gradlew assembleDebug --console rich
+  - ./gradlew assembleDebug