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/maxsonarez/maxsonarez.hpp

@@ -96,7 +96,7 @@ namespace upm {
      *
      * @return Distance to the object in inches
      */
-    virtual int getDistance();
+    virtual float getDistance();
 
   private:
     mraa_aio_context m_aio;