v2.0.0

• Fixed a bug with bad typescript typings
• Upgraded a bunch of devDependencies [including babel 6=>7]

I made it a major version because I wasn't sure how the potential change to transpile from preset-es2015 to preset-env. Also in case anything is dependent on the bugged behavior of the old typing.

v1.0.2

• Adding typescript typings. (#3)

v1.0.1

• Return unsubscribe function to caller (#1)