HARMONY-166: Remove multistage Docker build due to lack of CI/CD support

Dockerfile

@@ -1,29 +1,20 @@
 # Debian-based Python.  Builds _significantly_ faster than alpine due to presence of pre-built binaries for most libs
-FROM python:3.7.4-slim as base
+FROM python:3.7.4-slim
 
 WORKDIR "/home"
 
-# Multistage build https://docs.docker.com/develop/develop-images/multistage-build/
-# "builder" will have the ability to build dependencies.  "base" will be the actual image
-FROM base as builder
-
 # Install static things necessary for building dependencies.
 RUN pip3 install --upgrade pip
 RUN apt-get update && apt-get install -y build-essential
-RUN pip3 install cython
 
 # First run pip install against requirements.txt.  These take a while and are less likely to change than the service lib
 COPY requirements/core.txt requirements/core.txt
-RUN pip3 install --prefix='/install' --no-warn-script-location -r requirements/core.txt
+RUN pip3 install -r requirements/core.txt
 
 # Copy and install the service lib and its dependencies.
 COPY deps deps
-RUN pip3 install --prefix='/install' --no-warn-script-location deps/harmony-service-lib-py
-
-# Main image.  Copy built dependencies and local files
-FROM base
+RUN pip3 install deps/harmony-service-lib-py
 
-COPY --from=builder /install /usr/local
 COPY . .
 
 ENTRYPOINT ["python3", "-m", "harmony_netcdf_to_zarr"]