AP_Notify: example fix travis warning

missing function declaration
implicit cast
some style fix

libraries/AP_Notify/examples/AP_Notify_test/AP_Notify_test.cpp

@@ -7,6 +7,9 @@
 #include <AP_Notify/AP_Notify.h>          // Notify library
 #include <AP_Notify/AP_BoardLED.h>        // Board LED library
 
+void setup();
+void loop();
+
 const AP_HAL::HAL& hal = AP_HAL::get_HAL();
 
 // create board led object

libraries/AP_Notify/examples/ToshibaLED_test/ToshibaLED_test.cpp

@@ -2,6 +2,11 @@
 #include <AP_Notify/AP_Notify.h>
 #include <AP_Notify/ToshibaLED_I2C.h>
 
+void setup();
+void loop();
+void full_spectrum();
+void blink();
+
 const AP_HAL::HAL& hal = AP_HAL::get_HAL();
 
 static ToshibaLED_I2C toshiba_led;