Use codecov for coverage visualisation

.travis.yml

@@ -22,6 +22,8 @@ matrix:
         build_command: mvn -B -q clean package -DskipTests=true
         branch_pattern: master
   - jdk: openjdk8
+    after_success:
+      - bash <(curl -s https://codecov.io/bash)
   - jdk: oraclejdk9
     before_install:
         # The OpenJDK9's CA bundle is outdated, so we're using the system's ones.

README.md

@@ -8,6 +8,7 @@ Airsonic
 [![Coverity scan](https://scan.coverity.com/projects/17971/badge.svg)](https://scan.coverity.com/projects/airsonic)
 [![Language grade: JavaScript](https://img.shields.io/lgtm/grade/javascript/g/airsonic/airsonic.svg?logo=lgtm&logoWidth=18)](https://lgtm.com/projects/g/airsonic/airsonic/context:javascript)
 [![Language grade: Java](https://img.shields.io/lgtm/grade/java/g/airsonic/airsonic.svg?logo=lgtm&logoWidth=18)](https://lgtm.com/projects/g/airsonic/airsonic/context:java)
+[![codecov.io coverage](https://codecov.io/gh/airsonic/airsonic/branch/master/graph/badge.svg)](https://codecov.io/gh/airsonic/airsonic)
 
 What is Airsonic?
 -----------------

codecov.yml

@@ -0,0 +1 @@
+comment: false

pom.xml

@@ -333,6 +333,25 @@
         </pluginManagement>
 
         <plugins>
+            <plugin>
+                <groupId>org.jacoco</groupId>
+                <artifactId>jacoco-maven-plugin</artifactId>
+                <version>0.8.5</version>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>prepare-agent</goal>
+                        </goals>
+                    </execution>
+                    <execution>
+                        <id>report</id>
+                        <phase>test</phase>
+                        <goals>
+                            <goal>report</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-compiler-plugin</artifactId>