Oh, I forgot to mention something important. Ridiculously, the default
package repository Maven uses was not protected by SSL up until a few days
ago.  They made it available via SSL now, but you have to tell Maven about
the new URL. I guess they'll do a new release where SSL is the default
soon. But for now before you run mvn save the following magic incantation
to the path ~/.m2/settings.xml:

(side note: yes maven's love of XML is widely ridiculed and more modern
build tools have much better config languages, but we didn't upgrade yet)

<settings>
  <activeProfiles>
    <!--make the profile active all the time -->
    <activeProfile>securecentral</activeProfile>
  </activeProfiles>
  <profiles>
    <profile>
      <id>securecentral</id>
      <!--Override the repository (and pluginRepository) "central" from the
         Maven Super POM -->
      <repositories>
        <repository>
          <id>central</id>
          <url>https://repo1.maven.org/maven2</url>
          <releases>
            <enabled>true</enabled>
          </releases>
        </repository>
      </repositories>
      <pluginRepositories>
        <pluginRepository>
          <id>central</id>
          <url>https://repo1.maven.org/maven2</url>
          <releases>
            <enabled>true</enabled>
          </releases>
        </pluginRepository>
      </pluginRepositories>
    </profile>
  </profiles>
</settings>