Add Django 1.5 Compatibility to arm_wells

`arm_wells` is currently broken in Django 1.5 because the `MultipleObjectMixin.get_context_data` expects `object_list` to be passed into its kwargs. This *did not* change between Django 1.4 and 1.5. What *did* change is that `TemplateView` (which is above `MultipleObjectMixin` in the MRO), returned a dict and didn't go further up the MRO (https://github.com/django/django/blob/stable/1.4.x/django/views/generic/base.py#L117-L120 vs https://github.com/django/django/blob/stable/1.5.x/django/views/generic/base.py#L153)

### TODO
* [x] get Django 1.4 to work again
* [x] add test:  `object_list` should be in the context of a `QuerySetBackedWellView` view because it extends `MultipleObjectMixin` (this is a bug in the current version of `arm_wells`)
* [x] extend test coverage to django 1.5

### Addendum

Django 1.4.3:

    ipdb> QuerySetBackedWellView.__mro__
    (<class 'armstrong.core.arm_wells.views.QuerySetBackedWellView'>, <class 'armstrong.core.arm_wells.views.SimpleWellView'>, <class 'django.views.generic.base.TemplateView'>, <class 'django.views.generic.base.TemplateResponseMixin'>, <class 'django.views.generic.base.View'>, <class 'django.views.generic.list.MultipleObjectMixin'>, <type 'object'>)

Django 1.5.1

    ipdb> QuerySetBackedWellView.__mro__
    (<class 'armstrong.core.arm_wells.views.QuerySetBackedWellView'>, <class 'armstrong.core.arm_wells.views.SimpleWellView'>, <class 'django.views.generic.base.TemplateView'>, <class 'django.views.generic.base.TemplateResponseMixin'>, <class 'django.views.generic.list.MultipleObjectMixin'>, <class 'django.views.generic.base.ContextMixin'>, <class 'django.views.generic.base.View'>, <type 'object'>)