Fix examples.

.travis.yml

@@ -56,6 +56,7 @@ install:
     fi
   # Use clang 3.5
   - if [ "$CXX" = "clang++" ]; then export CXX="clang++-3.5"; export CC="clang-3.5"; fi
+  - arduino --install-library "MIDIUSB"
 
 script:
   # Build examples with Arduino IDE on each available platform / board

examples/Basic_IO/Basic_IO.ino

@@ -6,7 +6,7 @@
 
 MIDI_CREATE_DEFAULT_INSTANCE();
 
-static const ledPin = 13;               // LED pin on Arduino Uno
+static const unsigned ledPin = 13;      // LED pin on Arduino Uno
 
 void setup()
 {