Update CONTRIBUTING.md, fix Message/Send example

Author: FokkeZB

CONTRIBUTING.md

@@ -1,6 +1,9 @@
 ## Contributing
 
-We'd ❤️ to welcome your contribution. Please make sure you:
+We'd ❤️ to welcome your contribution. Please make sure your changes include:
 
-1.  Keep [keywords.txt](../keywords.txt) up to date with your changes.
-2.  Keep [API.md](../API.md) up to date with your changes.
+1.  Examples: [examples](examples)
+2.  Syntax highlighting: [keywords.txt](../keywords.txt)
+3.  Documentation: [docs](docs)
+4.  Tests: [test](test)
+5.  Verification of the examples and tests: [.travis.yml](.travis.yml)

examples/Message/Send/Send.ino

@@ -46,9 +46,8 @@ void loop() {
 
   // Encode the selected fields of the struct as bytes
   byte *buffer;
-  size_t buffer_size = 51;
   size_t size;
-  TheThingsMessage::encodeSensorData(&data, &buffer, buffer_size, &size);
+  TheThingsMessage::encodeSensorData(&data, &buffer, &size);
 
   ttn.sendBytes(buffer, size);