Bug with scons_tools

[pfernique]

Let consider the following commit StatisKit/LinAlg@0e4c802.
The libstatiskit_stl-wig Conda package has to be in both host and build dependencies in order to build the libstatiskit_linalg-wig Conda recipe in place of just host dependencies.
Otherwise, the following error is raised at build time:

scons: *** [/home/pfernique/Desktop/miniconda/conda-bld/libstatiskit_linalg-wig_1550649714218/_h_env_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placeh/lib/python3.7/site-packages/scons_tools/site_autowig/ASG/statiskit_linalg.pkl] ModuleNotFoundError : No module named 'scons_tools.site_autowig.controller.statiskit_stl'
Traceback (most recent call last):
  File "/home/pfernique/Desktop/miniconda/conda-bld/libstatiskit_linalg-wig_1550649714218/_build_env/lib/python3.7/site-packages/SCons/Action.py", line 1192, in execute
    result = self.execfunction(target=target, source=rsources, env=env)
  File "/home/pfernique/Desktop/miniconda/conda-bld/libstatiskit_linalg-wig_1550649714218/_build_env/lib/python3.7/site-packages/scons_tools/site_tools/pybind11_wig.py", line 114, in pybind11_builder
    **kwargs)
  File "/home/pfernique/Desktop/miniconda/conda-bld/libstatiskit_linalg-wig_1550649714218/_h_env_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placeh/lib/python3.7/site-packages/scons_tools/site_autowig/controller/statiskit_linalg.py", line 2, in controller
    from scons_tools.site_autowig.controller.statiskit_stl import controller as stl_controller
ModuleNotFoundError: No module named 'scons_tools.site_autowig.controller.statiskit_stl'
scons: building terminated because of errors.