travis build

different configurations are specified in the configurations directory
 to select one copy it replcing the config.h file (as the travis script does)
 or change the include file directive in crossbow.ino

crossbow/sbus.h

@@ -0,0 +1,25 @@
+
+#ifndef SBUS_INPUT
+#define SBUS_INPUT
+
+#include "Arduino.h"
+#include "tx_input.h"
+
+
+class SbusInput : public TxInput
+{
+  public:
+  	SbusInput(HardwareSerial &serial);
+    void start(void);
+    void loop(void);
+    bool isReceiving(void);
+  private:
+  	HardwareSerial &_serial;
+    uint32_t _lastChannelReceivedAt = 0;
+	void sbusRead(void);
+};
+
+void sbusPreparePacket(uint8_t packet[], int16_t channels[], bool isSignalLoss, bool isFailsafe);
+
+#endif
+