fix: add yarn gitignores (facebook#1507)

* fix: add yarn gitignores to template

* fix: add yarn gitignores to root

* fix: add wildcard to npm-debug.log ignore

Author: AndersDJohnson

.gitignore

@@ -5,5 +5,7 @@ build
 my-app*
 template/src/__tests__/__snapshots__/
 lerna-debug.log
-npm-debug.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
 /.changelog

packages/react-scripts/template/gitignore

@@ -12,4 +12,7 @@
 # misc
 .DS_Store
 .env
-npm-debug.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+