add python 3 docker test = fix lifo metaclass

docker/clone_and_test_python3.sh

@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+
+# install dev version
+git clone https://github.com/kalliope-project/kalliope.git kalliope;
+cd kalliope;
+git checkout dev;
+
+# install
+sudo python3 setup.py install
+
+# tests
+export LANG=C.UTF-8
+python3 -m unittest discover

docker/ubuntu_16_04.dockerfile

@@ -21,6 +21,7 @@ RUN pip install --upgrade pip six
 RUN pip install --upgrade pip pyyaml
 RUN pip install --upgrade pip SpeechRecognition
 RUN pip install --upgrade pip Werkzeug
+RUN pip install --upgrade pip gitdb
 
 # add a standart user. tests must not be ran as root
 RUN useradd -m -u 1000 tester

docker/ubuntu_16_04_python3.dockerfile

@@ -0,0 +1,38 @@
+# used to build the last kalliope dev version with python 3
+# docker build --force-rm=true -t kalliope-ubuntu1604-python3 -f docker/ubuntu_16_04_python3.dockerfile .
+# docker run -it --rm kalliope-ubuntu1604-python3
+
+FROM ubuntu:16.04
+
+ENV no_proxy="127.0.0.1,localhost,kalliope.fr"
+
+# set UTF-8 to the terminal
+ENV LANG en_US.UTF-8
+
+# pico2wav is a multiverse package
+RUN echo "deb http://us.archive.ubuntu.com/ubuntu/ xenial multiverse" >> /etc/apt/sources.list
+
+# install packages
+RUN apt-get update && apt-get install -y \
+    git python3-dev libsmpeg0 libttspico-utils libsmpeg0 flac dialog \
+    libffi-dev libffi-dev libssl-dev portaudio19-dev build-essential \
+    sox libatlas3-base mplayer wget vim sudo\
+    && rm -rf /var/lib/apt/lists/*
+
+# Install the last PIP
+RUN wget https://bootstrap.pypa.io/get-pip.py
+RUN python3 get-pip.py
+
+# add a standart user. tests must not be ran as root
+RUN useradd -m -u 1000 tester
+RUN usermod -aG sudo tester
+RUN echo '%sudo ALL=(ALL) NOPASSWD:ALL' >> /etc/sudoers
+
+ADD docker/clone_and_test_python3.sh /home/tester/clone_and_test_python3.sh
+RUN chown tester /home/tester/clone_and_test_python3.sh
+
+USER tester
+WORKDIR /home/tester
+
+# run tests
+CMD ./clone_and_test_python3.sh

kalliope/core/LIFOBuffer.py

@@ -34,7 +34,6 @@ class LIFOBuffer(with_metaclass(Singleton, object)):
     like with the Neurotransmitter neuron.
     
     """
-    __metaclass__ = Singleton
 
     def __init__(self):
         logger.debug("[LIFOBuffer] LIFO buffer created")