.travis-settings.xml

<?xml version="1.0" encoding="UTF-8"?>
<settings>
  <servers>
    <server>
      <id>ossrh</id>
      <username>${env.CENTRAL_USERNAME}</username>
      <password>${env.CENTRAL_PASSWORD}</password>
    </server>
    <server>
      <id>github</id>
      <password>${env.GITHUB_PASSWORD}</password>
    </server>
  </servers>
  <profiles>
    <profile>
      <id>ossrh</id>
      <activation>
        <activeByDefault>true</activeByDefault>
      </activation>
      <properties>
        <gpg.keyname>${env.GPG_KEY_NAME}</gpg.keyname>
        <gpg.passphrase>${env.GPG_PASSPHRASE}</gpg.passphrase>
      </properties>
    </profile>
    <profile>
      <id>allow-snapshots</id>
      <activation>
        <activeByDefault>true</activeByDefault>
      </activation>
      <repositories>
        <repository>
          <id>snapshots-repo</id>
          <url>https://oss.sonatype.org/content/repositories/snapshots</url>
          <releases>
            <enabled>false</enabled>
          </releases>
          <snapshots>
            <enabled>true</enabled>
          </snapshots>
        </repository>
      </repositories>
    </profile>
  </profiles>
</settings>