Add support for browsers

Add support for browser by adding a shim that uses performance.now when process.hrtime is not available. It uses browser-process-hrtime to do this.

ES6 support

• Code converted to ES6 style
• Add wrap support for generator functions

Refactored tests and fixed median

v1.1.0

v0.2.2

Version bump

v0.2.1

Switch to using process.hrtime() thus no dependencies are needed and the resolution is now nanoseconds.

v0.1.6 Small fixes and first github release

Update package.json