Added Travis CI & Coveralls.

app/build.gradle

@@ -1,4 +1,5 @@
 apply plugin: 'com.android.application'
+apply plugin: 'com.github.kt3k.coveralls'
 
 android {
     compileSdkVersion 25
@@ -41,3 +42,12 @@ dependencies {
     compile 'com.android.support:appcompat-v7:25.0.1'
     compile 'com.android.support:recyclerview-v7:25.0.1'
 }
+
+coveralls {
+    jacocoReportPath = "${buildDir}/reports/coverage/debug/report.xml"
+}
+
+tasks.coveralls {
+    dependsOn 'createDebugCoverageReport'
+    onlyIf { System.env.'CI' }
+}