Restrict Continuum notification to failures only.

For now, comment out the following section in the poms, then add the notifiers via the continuum web interface.

<ciManagement>
<system>continuum</system>
<notifiers>
<notifier>
<configuration>
<address>commits@myfaces.apache.org</address>
</configuration>
</notifier>
</notifiers>
</ciManagement>