Added change log for upcoming 4.0.0 release

Jacob Wenger · Jacob Wenger · commit 90571edd9904 · 2016-03-05T16:55:34.000-08:00
diff --git a/changelog.txt b/changelog.txt
@@ -0,0 +1,3 @@
+important - See the migration guide (https://github.com/firebase/geofire-js/tree/master/migration#upgrading-from-geofire-3xx-to-4xx) for upgrade instructions.
+changed - Removed the `rsvp` dependency in favor of internal Firebase promises.
+changed - Upgraded the `firebase` dependency to `^2.4.0` and made it a peer dependency instead of a regular dependency.

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,3 @@`
	`1`	`+important - See the migration guide (https://github.com/firebase/geofire-js/tree/master/migration#upgrading-from-geofire-3xx-to-4xx) for upgrade instructions.`
	`2`	+changed - Removed the `rsvp` dependency in favor of internal Firebase promises.
	`3`	+changed - Upgraded the `firebase` dependency to `^2.4.0` and made it a peer dependency instead of a regular dependency.