Temp patch to build docker container.

Dockerfile

@@ -5,6 +5,7 @@ WORKDIR     /usr/local
 ADD         . lakesuperior
 WORKDIR     /usr/local/lakesuperior
 RUN         git submodule update --init
+RUN         [[ -f lakesuperior/model/base.c ]] || pip install cython
 RUN         pip install -e .
 RUN         cp ./docker/etc/* ./lakesuperior/etc.defaults/
 CMD         ./docker/docker_entrypoint