added jacoco and coverall test coverage reports

.travis.yml

@@ -3,3 +3,6 @@ jdk:
   - oraclejdk8
   - oraclejdk7
   - openjdk7
+
+after_success:
+  - gradle jacocoTestReport coveralls

README.md

@@ -1,4 +1,5 @@
 [![Build Status](https://travis-ci.org/tools4j/meanvar.svg?branch=master)](https://travis-ci.org/tools4j/meanvar)
+[![Coverage Status](https://coveralls.io/repos/github/tools4j/meanvar/badge.svg?branch=master)](https://coveralls.io/github/tools4j/meanvar?branch=master)
 
 # tools4j-meanvar
 Tiny Java utility to incrementally calculate Mean and Standard Deviation with a numerically stable algorithm. Contains a simple utility class to incrementally calculate moving average and moving standard deviation of a data series. 

build.gradle

@@ -1,5 +1,7 @@
 apply plugin: 'java'
 apply plugin: 'license'
+apply plugin: 'jacoco'
+apply plugin: 'com.github.kt3k.coveralls'
 
 sourceCompatibility = 1.7
 group = "org.tools4j"
@@ -24,6 +26,7 @@ buildscript {
 
 	dependencies {
 		classpath 'nl.javadude.gradle.plugins:license-gradle-plugin:0.11.0'
+        	classpath "org.kt3k.gradle.plugin:coveralls-gradle-plugin:2.8.2"
 	}
 }
 
@@ -57,6 +60,13 @@ javadoc {
 	options.overview = "src/main/java/overview.html";
 }
 
+jacocoTestReport {
+    reports {
+        xml.enabled = true // coveralls plugin depends on xml format report
+        html.enabled = true
+    }
+}
+
 task javadocJar(type: Jar) {
     classifier = 'javadoc'
     from javadoc
@@ -69,4 +79,4 @@ task sourcesJar(type: Jar) {
 
 artifacts {
     archives javadocJar, sourcesJar
-}
+}