doc: remove python 2.7 reference (#231)

* doc: remove python 2.7 reference

* update badge year

* tox: remove py27

* rename to upgrade section

README.rst

@@ -40,7 +40,7 @@ canvas, and other functionality to support:
 * state management,
 * dithering to monochrome,
 * pygame emulator,
-* Python 2.7 and 3.5+ are both supported
+* Python 3.5 and newer are supported
 
 Documentation
 -------------
@@ -67,8 +67,8 @@ or `Ebay <http://www.ebay.com/itm/-/172317726225>`_.
 .. image:: https://raw.githubusercontent.com/rm-hull/luma.led_matrix/master/doc/images/emulator.gif
    :alt: max7219 emulator
 
-Breaking changes
-----------------
+Upgrade
+-------
 Version 0.3.0 was released on 19 January 2017: this came with a rename of the
 github project from **max7219** to **luma.led_matrix** to reflect the changing
 nature of the codebase.

doc/index.rst

@@ -15,7 +15,7 @@ Luma.LED_Matrix: Display drivers for MAX7219, WS2812, APA102
 .. image:: https://img.shields.io/pypi/v/luma.led_matrix.svg
    :target: https://pypi.python.org/pypi/luma.led_matrix
 
-.. image:: https://img.shields.io/maintenance/yes/2019.svg?maxAge=2592000
+.. image:: https://img.shields.io/maintenance/yes/2020.svg?maxAge=2592000
 
 .. toctree::
    :maxdepth: 2

tox.ini

@@ -2,7 +2,7 @@
 # See LICENSE.rst for details.
 
 [tox]
-envlist = py{27,35,36,37,38},qa,doc
+envlist = py{35,36,37,38},qa,doc
 skip_missing_interpreters = True
 
 [testenv]