[firebase-release] Removed change log and reset repo after 0.5.6 release

Author: firebase-ops

changelog.txt

@@ -1,4 +0,0 @@
-important - Update firebase-admin peer dependency to v4.2.1. Developer needs to run “npm install --save firebase-admin”  inside the functions directory.
-fixed - event.data.val() no longer returns array of nulls when the database node has a “length” key.
-fixed - Fixed bug where event.data.forEach(snapshot => {}) caused snapshot.key to be a concatenation of the parent and child keys.
-fixed - Fixed bug where nested storage objects had literal slashes in mediaLink property, instead of URL-escaped slashes.