Merge pull request #1 from dlawrences/dev/coreml_convert_pxscaling

Updated coreml conversion to do pixel scaling between 0.0 and 1.0

models/export.py

         import coremltools as ct
 
         print('\nStarting CoreML export with coremltools %s...' % ct.__version__)
-        model = ct.convert(ts, inputs=[ct.ImageType(name='images', shape=img.shape)])  # convert
+        # convert model from torchscript and apply pixel scaling as per detect.py
+        model = ct.convert(ts, inputs=[ct.ImageType(name='images', shape=img.shape, scale=1/255.0, bias=[0, 0, 0])])
         f = opt.weights.replace('.pt', '.mlmodel')  # filename
         model.save(f)
         print('CoreML export success, saved as %s' % f)