updated/simplified associations and added models for vaccination, length, and weight
updated seed file to reflect new models
shrunk routes so that they are all nested; updated crud methods in controllers to reflect this change
pets controller and model all set
medications controller all set
conditions controller all set
added lengths and widths controllers
added vaccinations and fixed show methods in all controllers
Merge pull request #4 from ShaynaCummings/updating_models

Updating models