Unit Conversion

This function converts certain units of time, distance, speed, weight, and volume.

Provide three inputs for the function. The first is the value you would like to convert. The second is the current units of that value, and the third is the units you would like to convert your value to. All inputs must be strings in order for the code to run properly. All conversion rates are based on Google's unit conversion machine, except for Cups to ml, which is based on a more accurate estimate than google provides.