[m2] sequencing goals

[dohadwala, moiz]

I have a custom plugin with 3 goals. They are separate becuase I need to be
able to execute each one individually.
They all bind to the same lifecycle phase. 
 
However, when the plugin is included in the build section, I need to be able
to execute all 3 goals, but in a pre-defined order: 
goal1->goal2>goal3.
 
How do I enforce this in the plugin? If not, do I have to move them to
separate plugins? Then how do I enforce order between the plugins?
 
-Moiz