Oops - made the readme markdown without telling setup.py

Fixes issue #3

Author: dannystaple

setup.py

@@ -6,8 +6,8 @@
     packages=['usb_arm',],
     author="Danny Staple - Orionrobots",
     license='Creative Commons By Attribution Share-Alike v3.0',
-    long_description=open('README.txt').read(),
+    long_description=open('README.md').read(),
     install_requires=[
         "pyusb"
     ]
-)
+)