use navigator.sendBeacon when available [KNOWN ISSUE]

KNOWN ISSUE: this release contains a known issue, read more at #10

New API and bugfixes

• Replace StackdriverErrorReporting with StackdriverErrorReporter
• Replace .init() with .start()
• Fixes a bug that prevented to opt-out of reporting unhandled exceptions.

do not override window.onerrior

v0.0.3

bump version

Public source maps support

v0.0.2

dist v0.0.2

Experimental first release

v0.0.1

update README install instructions for new file name