tests.username and tests.password need to be configured in your ~/.m2/settings.xml like this:
<?xml version="1.0" encoding="UTF-8"?>
<settings>
...
<profiles>
<profile>
<id>amenlib-properties</id>
<properties>
<tests.username>email@some.domain</tests.username>
<tests.password>mypass</tests.password>
</properties>
</profile>
</profiles>
...
<activeProfiles>
<activeProfile>amenlib-properties</activeProfile>
</activeProfiles>
</setting>