bash$ mvn clean install -DskipTests
혹은
bash$ mvn clean install -Dmaven.test.skip=true

<project>
  [...]
  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-surefire-plugin</artifactId>
        <version>2.19.1</version>
        <configuration>
          <skipTests>true</skipTests>
        </configuration>
      </plugin>
    </plugins>
  </build>
  [...]
</project>

or

<project>
  [...]
  <properties>
    <skipTests>true</skipTests>
  </properties>
  [...]
  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-surefire-plugin</artifactId>
        <version>2.19.1</version>
        <configuration>
          <skipTests>${skipTests}</skipTests>
        </configuration>
      </plugin>
    </plugins>
  </build>
  [...]
</project>

リファレンス