Use smbus2 - fixes #28

No noticeable performance impact of using smbus2 over sambas

README.rst

@@ -104,12 +104,12 @@ Then add your user to the i2c group::
 
 Install some packages (python2)::
 
-  $ sudo apt-get install i2c-tools python-smbus python-pip libfreetype6-dev libjpeg8-dev
+  $ sudo apt-get install i2c-tools python-pip libfreetype6-dev libjpeg8-dev
   $ sudo pip install pillow
 
 or (python3)::
 
-  $ sudo apt-get install i2c-tools python3-smbus python3-pip libfreetype6-dev libjpeg8-dev
+  $ sudo apt-get install i2c-tools python3-pip libfreetype6-dev libjpeg8-dev
   $ sudo pip3 install pillow
 
 Next check that the device is communicating properly (if using a rev.1 board, 

oled/device.py

@@ -50,7 +50,7 @@
 # As before, as soon as the with block completes, the canvas buffer is flushed
 # to the device
 
-import smbus
+import smbus2
 from PIL import Image
 
 
@@ -62,7 +62,7 @@ class device(object):
     def __init__(self, bus=None, port=1, address=0x3C, cmd_mode=0x00, data_mode=0x40):
         self.cmd_mode = cmd_mode
         self.data_mode = data_mode
-        self.bus = bus or smbus.SMBus(port)
+        self.bus = bus or smbus2.SMBus(port)
         self.addr = address
 
     def command(self, *cmd):

requirements.txt

@@ -1 +1,2 @@
-pillow
+pillow
+smbus2

setup.py

@@ -17,7 +17,7 @@
     url = "https://github.com/rm-hull/ssd1306",
     download_url = "https://github.com/rm-hull/ssd1306/tarball/0.3.2",
     packages=['oled'],
-    install_requires = ["pillow"],
+    install_requires = ["pillow", "smbus2"],
     classifiers = [
         "License :: OSI Approved :: MIT License",
         "Development Status :: 4 - Beta",