Test to verify behavior of HaProvider service with only a single URL

Write a unit test to verify that a service with an HaProvider configuration, but only a single URL in the corresponding service declaration, doesn't break the provider.

<provider>
<role>ha</role>
<name>HaProvider</name>
<enabled>true</enabled>
<param>
<name>OOZIE</name>
<value>maxFailoverAttempts=3;failoverSleep=1000;enabled=true</value>
</param>
</provider>
...
<service>
<role>OOZIE</role>
<url>http://host:port/oozie</url>
</service>

The HaProvider should always use the single URL without error, even though it's not really HA at that point.