Determine an URI based on the base URI and provided options (for the body_weight and body_fat methods).
Added the body_weight method.
Added the body_fat method.
Added the body_weight_goal method.
Added the body_fat_goal method.
These aren't actually update methods, they're retrieval methods.
Merge pull request #18 from kevintuhumury/master

Add support for Body Weight, Body Weight Goal, Body Fat and Body Fat Goal