python2: remove ability to build python2 bindings from project

This removes Python 2 package generation from the project to encourage safer development with Python 3 instead. Documentation for the generated modules switched to Python 3. Default interpreter is now Python 3 but can be overridden if needed for running the tests only on older environments.

Signed-off-by: Mihai Tudor Panu <mihai.tudor.panu@intel.com>

src/python/python3/docs/example.rst

@@ -0,0 +1,103 @@
+#######
+Example
+#######
+Here are some examples of how to use mraa, common convention is to import mraa
+as mraa to keep it short but feel free to import it globally! As a general rule
+the API is very similar to the C++ API so there are only basic examples to show
+quick usage. The mraa module can be built with python3 or python2. All examples
+may not run on python3 as this is not tested.
+
+Hello GPIO
+==========
+
+Here is the simplest Gpio program in mraa.
+
+.. literalinclude:: ../../../../examples/python/gpio.py
+  :prepend: import mraa
+  :start-after: import mraa
+
+GPIO Interrupt (isr)
+====================
+
+The GPIO module allows you to set an interrupt on a GPIO. This interrupt is
+controlled by the mode that the 'edge' is in. Before setting another isr please
+remove the first one, multiple isrs on one pin are not supported. Some
+platforms will not support interrupts on all pins so please check your return
+values.
+
+**Note:** Galileo Gen1 only supports EDGE_BOTH
+
+.. literalinclude:: ../../../../examples/python/gpio_advanced.py
+  :prepend: import mraa
+  :start-after: import mraa
+
+**Note:** If the python script is ended the destructors will run meaning that
+the ISR will not run. The sleep call is there for that function.
+
+**Note:** The python isr module treats only objects. This means that int
+counters will not work inside your isr. Please use the different edge modes.
+
+I2c
+===
+
+The I2c module module has a number of different ways of interacting with the
+i2c bus, including a number of overloaded read() calls and the writeReg()
+helper function.
+
+.. literalinclude:: ../../../../examples/python/i2c_bmp85.py
+  :prepend: x = m.I2c(0)
+  :start-after: x = m.I2c(0)
+
+.. literalinclude:: ../../../../docs/i2c.txt
+
+Pwm
+===
+
+The PWM module is rather simple, note that different hardware support PWM
+generation is various different ways so results may vary.
+
+.. literalinclude:: ../../../../examples/python/pwm.py
+  :prepend: import mraa
+  :start-after: import mraa
+
+Aio
+===
+
+The ADC is typically provided on a dedicated or shared SPI bus, this is
+abstracted by the Linux kernel as spidev and abstracted again by mraa. It is
+fairly simple in use.
+
+.. literalinclude:: ../../../../examples/python/aio.py
+  :prepend: import mraa
+  :start-after: import mraa
+
+Uart
+====
+
+Uart is the Universal asynchronous receiver/transmitter interface in mraa.
+It allows the exposure of UART pins on supported boards, with basic
+configuration operations supported.
+
+Here's a simple pair of programs comprising a sender and receiver pair.
+
+Sender:
+
+.. literalinclude:: ../../../../examples/python/uart_sender.py
+  :prepend: import mraa
+  :start-after: import mraa
+
+Receiver:
+
+.. literalinclude:: ../../../../examples/python/uart_receiver.py
+  :prepend: import mraa
+  :start-after: import mraa
+
+LED
+===
+
+LED module is used for controlling the on-board LEDs. With the
+help of this module, we can control the brightness, trigger etc...
+
+.. literalinclude:: ../../../../examples/python/led.py
+  :prepend: import mraa
+  :start-after: import mraa