Added contributing file

Stefan Kremser · Stefan Kremser · commit 5abaefa5c281 · 2017-07-23T15:00:33.000+02:00
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
@@ -0,0 +1,2 @@
+Please only make pull requests to the [testing branch](https://github.com/spacehuhn/esp8266_deauther/tree/testing) to avoid future conflicts.  
+The `testing` branch is merged with `master` on every release. 

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	`+Please only make pull requests to the [testing branch](https://github.com/spacehuhn/esp8266_deauther/tree/testing) to avoid future conflicts.`
	`2`	+The `testing` branch is merged with `master` on every release.