integrate with coveralls.io

.travis.yml

 language: java
+
+after_success:
+  - mvn clean cobertura:cobertura coveralls:report
\ No newline at end of file

core/pom.xml

 <?xml version="1.0" encoding="UTF-8"?>
 <!--
     Description: B3log Solo core.
-    Version: 2.0.1.7, Oct 16, 2014
+    Version: 2.1.1.7, Dec 31, 2014
     Author: Liang Ding
 -->
 <project xmlns="http://maven.apache.org/POM/4.0.0"
@@ -132,6 +132,19 @@
                 </executions>
             </plugin>
             
+            <plugin>
+                <groupId>org.eluder.coveralls</groupId>
+                <artifactId>coveralls-maven-plugin</artifactId>
+                <version>${coveralls-maven-plugin.version}</version>
+                <configuration>
+                    <repoToken>PmmgdTzVuYQAsiOHNZ67bNDuqwDRSKvlm</repoToken>
+                    <format>xml</format>
+                    <maxmem>256m</maxmem>
+                    <!-- aggregated reports for multi-module projects -->
+                    <aggregate>true</aggregate>
+                </configuration>
+            </plugin>
+            
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-surefire-plugin</artifactId>

pom.xml

 <?xml version="1.0" encoding="UTF-8"?>
 <!--
     Description: B3log Solo parent POM.
-    Version: 2.0.4.16, Dec 6, 2014
+    Version: 2.1.4.16, Dec 31, 2014
     Author: Liang Ding
 -->
 <project xmlns="http://maven.apache.org/POM/4.0.0"
@@ -45,7 +45,8 @@
         <maven-checkstyle-plugin.version>2.7</maven-checkstyle-plugin.version>
         <maven-javancss-plugin.version>2.0</maven-javancss-plugin.version>
         <maven-javadoc-plugin.version>2.7</maven-javadoc-plugin.version>
-        <maven-cobertura-plugin.version>2.5.1</maven-cobertura-plugin.version>
+        <maven-cobertura-plugin.version>2.6</maven-cobertura-plugin.version>
+        <coveralls-maven-plugin.version>3.0.1</coveralls-maven-plugin.version>
         <maven-min-plugin.version>1.0.0</maven-min-plugin.version>
         <!-- Unit Test -->
         <testng.version>6.1.1</testng.version>