updated readme files in test directory

Author: soundanalogous

test/readme.md

@@ -1,3 +1,7 @@
 #Testing Firmata
 
-TO DO: overview of firmata testing process.
+The Firmata test suite includes unit tests (see the unit directory). Integration
+tests may also be added at some point in the future.
+
+If you make changes to Firmata.cpp, run the tests in /test/unit/ to ensure
+that your changes have not produced any unexpected errors.

test/unit/readme.md

@@ -1,4 +1,8 @@
 #Firmata Unit Tests
 
-TO DO: instructions on running unit tests and creating new tests for new
-features.
+Unit tests are written using the [ArduinoUnit](https://github.com/mmurdoch/arduinounit) library (version 2.0).
+
+Follow the instructions in the [ArduinoUnit readme](https://github.com/mmurdoch/arduinounit/blob/master/readme.md) to install the library.
+
+Compile and upload the test sketch as you would any other sketch. Then open the 
+Serial Monitor to view the test results.