v2.2.0 - Smaller build, CJS + ESM via Rollup

Many thanks to @TrySound for a lot of the recent updates 🎉

0e5d9f7 Remove prop-types in production (#28)
f9a47d1 Enable babel loose mode to reduce library size (#27)
b763e32 Add babel runtime to reuse helpers across packages (#25)
5569b79 Upgrade to babel 7 (#24)
16825f9 Bundle cjs and esm with rollup (#22)