Support JDK 9 and 10 on Travis CI

Fixes gh-275

Author: kazuki43zoo

.travis.yml

@@ -4,6 +4,8 @@ sudo: false
 jdk:
   - oraclejdk11
   - openjdk11
+  - openjdk10
+  - oraclejdk9
   - oraclejdk8
   - openjdk8
 

pom.xml

@@ -127,6 +127,34 @@
   </build>
 
   <profiles>
+    <profile>
+      <id>jdk9</id>
+      <activation>
+        <jdk>9</jdk>
+      </activation>
+      <dependencies>
+        <dependency>
+          <groupId>javax.annotation</groupId>
+          <artifactId>javax.annotation-api</artifactId>
+          <version>1.3.2</version>
+          <scope>test</scope>
+        </dependency>
+      </dependencies>
+    </profile>
+    <profile>
+      <id>jdk10</id>
+      <activation>
+        <jdk>10</jdk>
+      </activation>
+      <dependencies>
+        <dependency>
+          <groupId>javax.annotation</groupId>
+          <artifactId>javax.annotation-api</artifactId>
+          <version>1.3.2</version>
+          <scope>test</scope>
+        </dependency>
+      </dependencies>
+    </profile>
     <profile>
       <id>jdk11</id>
       <activation>