修复github-ci失败的问题

Author: dongchenxu

.travis.yml

@@ -1,20 +1,12 @@
 language: generic
 
-jdk:
-  - openjdk6
-  - oraclejdk6
-  - openjdk7
-  - oraclejdk7
-  - openjdk8
-  - oraclejdk8
-
-
 cache:
   directories:
     - "$HOME/.m2/repository"
 
 script:
-  - mvn -v
+  - export JAVA_HOME=$HOME/openjdk8
+  - $TRAVIS_BUILD_DIR/install-jdk.sh --install openjdk8 --target $JAVA_HOME
   - mvn -PgithubCI -X clean cobertura:cobertura -Dmaven.test.skip=false
 
 after_success:

sandbox-core/pom.xml

@@ -77,8 +77,7 @@
             <artifactId>tools</artifactId>
             <version>1.8</version>
             <scope>system</scope>
-<!--            <systemPath>${tools-jar}</systemPath>-->
-            <systemPath>${java.home}/lib/tools.jar</systemPath>
+            <systemPath>${tools-jar}</systemPath>
         </dependency>
 
         <dependency>