* Added component module that holds CratersComponent class.
* Added component module that holds CratersComponent class.

Added
=====

* New CratersComponent class that gives a potential landlab interface to
  the craters module.



amandersillinois/landlab,SiccarPoint/landlab,RondaStrauch/landlab,laijingtao/landlab,RondaStrauch/landlab,ManuSchmi88/landlab,landlab/landlab,decvalts/landlab,SiccarPoint/landlab,amandersillinois/landlab,cmshobe/landlab,decvalts/landlab,Carralex/landlab,RondaStrauch/landlab,Carralex/landlab,cmshobe/landlab,Carralex/landlab,landlab/landlab,ManuSchmi88/landlab,ManuSchmi88/landlab,csherwood-usgs/landlab,cmshobe/landlab,landlab/landlab,laijingtao/landlab,csherwood-usgs/landlab