Use jcgay-build-configuration as parent pom
Use latest mockito version
Can write test(s) with Groovy
Add AssertJ as dependency
Rename variable
Add a notifier using send-notification
Forward maven-notifier.properties configuration

Properties defined in maven-notifier.properties are added to
send-notification configuration instead of only relying on send-notification
configuration file.
Remove deprecated notifiers

As notifications now rely on send-notification, we don't need notifiers
implementation anymore.
Use send-notification notifier

When choosen notifier implementation is not equals to 'sound'
we should delegate notifications to send-notification.

This is a shortcut as the only notifier remaining in maven-notifier
is the one using sound.
Move code under package fr.jcgay.maven
Implements #onFailWithoutProject for send-notification

This is called when a build failed in early stage (malformed pom.xml for example)
Move message construction in SendNotificationNotifier

This is the last implementation which needs to build message.
It doesn't need to stay on AbstractCustomEventSpy anymore.
Add .editorconfig

See http://editorconfig.org for configuration and plugins
Convert test in Groovy
Override implementation is read while parsing configuration

Instead of checking System property in #shouldNotify, read the property while reading properties.
It will works with send-notification to as we override 'notifier.implementation' property instead
of changing chosen notifier in Maven EventSpy.
Use latest version
Build with TravisCI
Convert test in Groovy