Refactor to make test case subclassable
Refactor to make test case subclassable

Am getting ready to add another test case that's a sub-class of
SimpleWellView.  This refactor makes it easy to add sub-classes that
test another view but still run all of these tests.

armstrong/armstrong.core.arm_wells,texastribune/armstrong.core.arm_wells,dmclain/armstrong.core.arm_wells,dmclain/armstrong.core.arm_wells,armstrong/armstrong.core.arm_wells,armstrong/armstrong.core.arm_wells,texastribune/armstrong.core.arm_wells