Using Ubuntu 18.04 as reference system for tests, fixing minimal requirements accordingly

.gitlab-ci.yml

 # run the test suite
 
-tests_old_ubuntu:
-    image: registry.gitlab.lis-lab.fr:5005/skmad-suite/madarrays/ubuntu:16.04
-    tags:
-        - docker
-    script:
-        - pip3 install . --no-deps
-        - pytest
-
-tests_new_ubuntu:
-    image: registry.gitlab.lis-lab.fr:5005/skmad-suite/madarrays/ubuntu:rolling
+tests:
+    image: registry.gitlab.lis-lab.fr:5005/skmad-suite/madarrays/ubuntu:18.04
     tags:
         - docker
     script:
@@ -20,7 +12,7 @@ tests_new_ubuntu:
 # generate the documentation
 
 pages:
-    image: registry.gitlab.lis-lab.fr:5005/skmad-suite/madarrays/ubuntu:rolling
+    image: registry.gitlab.lis-lab.fr:5005/skmad-suite/madarrays/ubuntu:18.04
     tags:
         - docker
     only:

doc/installation.rst

@@ -4,13 +4,13 @@ Installation
 ``madarrays`` requires the following packages:
 
 * `python >= 3.5 <https://wiki.python.org/moin/BeginnersGuide/Download>`_
-* `numpy >= 1.11 <http://www.numpy.org>`_
-* `scipy >= 0.17 <https://www.scipy.org/scipylib/index.html>`_
-* `matplotlib >= 1.5 <http://matplotlib.org/>`_
+* `numpy >= 1.13 <http://www.numpy.org>`_
+* `scipy >= 0.19 <https://www.scipy.org/scipylib/index.html>`_
+* `matplotlib >= 2.1 <http://matplotlib.org/>`_
 * `simpleaudio >= 1.0 <https://github.com/hamiltron/py-simple-audio>`_
 * `resampy >= 0.2 <https://github.com/bmcfee/resampy>`_
 
-Make sure you Python environment is properly configured. It is recommended to
+Make sure your Python environment is properly configured. It is recommended to
 install ``madarrays`` in a virtual environment.
 
 Release version

docker/Dockerfile_ubuntu_16.04

-FROM ubuntu:16.04
-MAINTAINER Florent Jaillet
-WORKDIR /
-RUN apt-get update && \
-    apt-get install -y --no-install-recommends \
-        python3 \
-        python3-pip \
-        python3-wheel \
-        python3-setuptools \
-        python3-numpy\
-        python3-scipy \
-        python3-matplotlib \
-        ipython3 \
-        python3-six \
-        python3-dev \
-        gcc \
-        libasound2-dev \
-        && \
-    apt-get clean
-RUN mkdir -p /root/.config/matplotlib && \
-    echo "backend: pdf" > /root/.config/matplotlib/matplotlibrc
-RUN pip3 install llvmlite numba resampy simpleaudio --no-deps
-RUN pip3 install pytest pytest-cov pytest-randomly

docker/Dockerfile_ubuntu_rolling → docker/Dockerfile_ubuntu_18.04

-FROM ubuntu:rolling
+FROM ubuntu:18.04
 MAINTAINER Florent Jaillet
 WORKDIR /
+ENV DEBIAN_FRONTEND noninteractive
 RUN apt-get update && \
+    apt-get upgrade -y && \
     apt-get install -y --no-install-recommends \
         python3 \
         python3-pip \
@@ -10,6 +12,7 @@ RUN apt-get update && \
         python3-numpy\
         python3-scipy \
         python3-matplotlib \
+        python3-ltfatpy \
         ipython3 \
         python3-six \
         python3-numba \

requirements/defaults.txt

 --index-url https://pypi.python.org/simple/
 
-numpy>=1.11
-scipy>=0.17
-matplotlib>=1.5
+numpy>=1.13
+scipy>=0.19
+matplotlib>=2.1
 simpleaudio>=1.0
 resampy>=0.2