Change infrastructure to allow using java8-isms.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=237860437

.travis.yml

@@ -9,7 +9,6 @@ jdk:
   - oraclejdk11
   - oraclejdk9
   - oraclejdk8
-  - openjdk7
 
 env:
   global:

build.xml

@@ -116,8 +116,8 @@
         <pathelement location="${build.dir}/dist/guice-${version}.jar"/>
         <pathelement location="lib/javax.inject.jar"/>
         <pathelement location="lib/aopalliance.jar"/>
-        <pathelement location="lib/guava-25.1-android.jar"/>
-        <pathelement location="lib/build/guava-testlib-25.1-android.jar"/>
+        <pathelement location="lib/guava-27.1-jre.jar"/>
+        <pathelement location="lib/build/guava-testlib-27.1-jre.jar"/>
         <pathelement location="lib/build/junit.jar"/>
         <pathelement location="lib/build/servlet-api-2.5.jar"/>
         <pathelement location="lib/build/truth-0.41.jar"/>

common.xml

@@ -14,7 +14,7 @@
     <javac srcdir="${src.dir}"
          debug="on"
          destdir="${build.dir}/classes"
-         source="1.7" target="1.7" includeantruntime="false">
+         source="1.8" target="1.8" includeantruntime="false">
       <compilerarg value="-Xlint:all,-serial"/>
       <classpath refid="compile.classpath"/>
     </javac>

pom.xml

@@ -144,12 +144,12 @@ See the Apache License Version 2.0 for the specific language governing permissio
       <dependency>
         <groupId>com.google.guava</groupId>
         <artifactId>guava</artifactId>
-        <version>25.1-android</version>
+        <version>27.1-jre</version>
       </dependency>
       <dependency>
         <groupId>com.google.guava</groupId>
         <artifactId>guava-testlib</artifactId>
-        <version>25.1-android</version>
+        <version>27.1-jre</version>
       </dependency>
       <dependency>
         <groupId>org.ow2.asm</groupId>
@@ -265,14 +265,14 @@ See the Apache License Version 2.0 for the specific language governing permissio
           </executions>
         </plugin>
         <!--
-         | Make sure we only use Java7 methods
+         | Make sure we only use Java8 methods
         -->
         <plugin>
           <artifactId>maven-compiler-plugin</artifactId>
           <version>2.3.2</version>
           <configuration>
-            <source>1.7</source>
-            <target>1.7</target>
+            <source>1.8</source>
+            <target>1.8</target>
           </configuration>
         </plugin>
         <plugin>
@@ -282,13 +282,13 @@ See the Apache License Version 2.0 for the specific language governing permissio
           <configuration>
             <signature>
               <groupId>org.codehaus.mojo.signature</groupId>
-              <artifactId>java17</artifactId>
+              <artifactId>java18</artifactId>
               <version>1.0</version>
             </signature>
           </configuration>
           <executions>
             <execution>
-              <id>check-java-1.7-compat</id>
+              <id>check-java-1.8-compat</id>
               <phase>process-classes</phase>
               <goals>
                 <goal>check</goal>