Release Notes: Refactoring of the oil categorization methods. Some common functionality is now shared and some operations have been simplified. Adjusted criteria for diesel category. Refactored get_oil(). Removed some redundant exception handling. Created parsing methods for Environment Canada data sheets. Implemented an alternate determination of viscosity as a function of temperature. Research for this has been added to the viscosity notebook. Implemented a blacklist/whitelist method for oil categories. Applied some changes to the generic oils data file.