DOC fix autodoc not working on RTD

doc/conf.py

@@ -18,7 +18,7 @@ import os
 # If extensions (or modules to document with autodoc) are in another directory,
 # add these directories to sys.path here. If the directory is relative to the
 # documentation root, use os.path.abspath to make it absolute, like shown here.
-#sys.path.insert(0, os.path.abspath('.'))
+sys.path.insert(0, os.path.abspath('..'))
 
 # -- General configuration ------------------------------------------------
 

doc/requirements.txt

@@ -0,0 +1,4 @@
+pyusb
+Pillow>=2.0
+qrcode>=4.0
+pyserial