try to use pip to full extent

ci/install_basics.sh

 #!/bin/bash
 
-apt-get install -y build-essential  git autoconf libtool \
+apt-get install -y build-essential  git autoconf libtool pkg-config \
   libfftw3-bin libfftw3-dev libfftw3-double3 libfftw3-long3 libfftw3-quad3 libfftw3-single3 \
   python python-pip python-dev python-nose \
   python3 python3-pip python3-dev python3-nose

setup.py

@@ -32,7 +32,7 @@ setup(name="nifty2go",
       dependency_links=[
                'git+https://gitlab.mpcdf.mpg.de/ift/pyHealpix.git@setuptools_test#egg=pyHealpix-0.0.1'],
       license="GPLv3",
-      setup_requires=['future', 'pyHealpix>=0.0.1', 'numpy>=1.13', 'pyfftw>=0.10.4', 'matplotlib'],
+      setup_requires=['future', 'pyHealpix>=0.0.1', 'numpy>=1.13', 'pyfftw>=0.10.4'],
       classifiers=[
         "Development Status :: 4 - Beta",
         "Topic :: Utilities",