Changelog for v0.2.0 (#56)

* Changelog for v0.2.0

* Update changelog.txt

* Update changelog.txt

Co-authored-by: Bryan Kendall <[email protected]>

Author: laurenzlong

CHANGELOG.md

@@ -0,0 +1,4 @@
+* [breaking] Update peer dependency requirement for *firebase-functions* to be v2.0.0 or above, and for *firebase-admin* to be v6.0.0 or above.
+* Support scheduled functions (pull request #51).
+* Support null value in `test.database.makeDataSnapshot` (issue #48).
+* Support `rawRequest` in the callable context object for a wrapped HTTP Callable function (issue #41).