Delete and gitignore unwanted lock files (#4899)

Summary:
This diff deletes unnecessary lock files which were checked out but aren't necessary and `gitignore` those files:
- `yarn.lock`
- `js/yarn.lock`
- `react-native/yarn.lock`

## Changelog

[General] [Removed] - Delete unnecessary lock files.

Pull Request resolved: https://github.com/facebook/flipper/pull/4899

Test Plan: - None

Reviewed By: aigoncharov

Differential Revision: D47755862

Pulled By: passy

fbshipit-source-id: 8e9a03b59df1a2891004de3edbd9c3569d2d6055

.gitignore

@@ -14,6 +14,14 @@ manifest.json
 # conflicts with FB internal infra
 .watchmanconfig
 
+# Don't checkout the yarn/npm lock files that we don't need
+./yarn.lock
+./package-lock.json
+js/yarn.lock
+js/package-lock.json
+react-native/yarn.lock
+react-native/package-lock.json
+
 # iOS / Xcode
 *.xcworkspace
 **/Pods/

js/yarn.lock

@@ -1,4 +0,0 @@
-# THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.
-# yarn lockfile v1
-
-

react-native/yarn.lock

@@ -1,4 +0,0 @@
-# THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.
-# yarn lockfile v1
-
-

yarn.lock

@@ -1,4 +0,0 @@
-# THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.
-# yarn lockfile v1
-
-