fix: remove deprecated dockerfile

docker/cpu/cpu.dockerfile

@@ -0,0 +1,24 @@
+FROM continuumio/miniconda3:4.7.10
+
+# install tensorflow
+RUN conda install -y tensorflow==1.14.0
+
+# install ffmpeg for audio loading/writing
+RUN conda  install -y -c conda-forge ffmpeg
+
+# install extra python libraries
+RUN conda install -y -c anaconda pandas==0.25.1
+RUN conda install -y -c conda-forge libsndfile
+
+# install ipython
+RUN conda install -y ipython
+
+WORKDIR /workspace/
+COPY ./ spleeter/
+
+RUN mkdir /cache/
+
+WORKDIR /workspace/spleeter
+RUN pip install .
+
+ENTRYPOINT ["python", "-m", "spleeter"]