Merge pull request #53 from bjornstar/develop

v0.0.11: Added an 'is' method to indicate whether or not a Tome is obser...
v0.0.12: Changed readable to only include a value when a primitive value changes, but not when it changes types.
Merge pull request #54 from bjornstar/develop

v0.0.12 - Changed readable to only emit what a primitive value was
fixed typo it's -> its.
Merge pull request #16 from bjornstar/master

v0.0.12: Changed readable to only have a value when a primitive changes.