Merge branch 'release/1.2.1'
Merge branch 'develop'
Merge branch 'develop'
Merge branch 'develop'
Merge branch 'release/2.0.0'
adding volume unit

volume unit has support for :
gallon, quart, pint, cup, tablespoon, teaspoon, fluidounce

base unit: fluidounce
Merge pull request #4 from rozmichelle/master

Added Volume Unit