Modified all iDistance sensors to return float.

Signed-off-by: Serban Waltter <serban.waltter@rinftech.com>
Signed-off-by: Mihai Tudor Panu <mihai.tudor.panu@intel.com>

src/ultrasonic/ultrasonic.cxx

@@ -55,7 +55,7 @@ UltraSonic::~UltraSonic () {
     mraa_gpio_close (m_pinCtx);
 }
 
-int
+float
 UltraSonic::getDistance () {
 
     // output trigger signal

src/ultrasonic/ultrasonic.hpp

@@ -80,7 +80,7 @@ class UltraSonic {
          * Divide by 58 to convert distance to centimetres. 
          * Divide by 148 to convert distance to inches.
          */
-        int getDistance ();
+        float getDistance ();
 
         /**
          * Return name of the component
@@ -93,7 +93,7 @@ class UltraSonic {
         /**
          * Returns true while the sensor is busy waiting for the echo pulse
          */
-        bool working()
+        float working()
         {
             return m_doWork;
         }