Improve docker caching in Dockerfile-ModelServer

Moved the adding of build.sh to the end, so the ModelServer dockerfile
shares as many lines as possible with ModelBuilder, so their
docker layers will be shared.

Dockerfile-ModelBuilder

@@ -16,15 +16,16 @@ FROM python:3.6.8-slim-stretch
 COPY requirements.txt /code/
 RUN pip install -r /code/requirements.txt
 
+# Install gordo-components, packaged from earlier 'python setup.py sdist'
+COPY --from=builder /code/dist/gordo-components-packed.tar.gz .
+
+# Install gordo-components, packaged from earlier 'python setup.py sdist'
+RUN pip install ./gordo-components-packed.tar.gz
+
 ADD build.sh /code/build.sh
 
 # build.sh (build the model) as executable default command
 RUN cp /code/build.sh /usr/bin/build \
     && chmod +x /usr/bin/build
 
-# Install gordo-components, packaged from earlier 'python setup.py sdist'
-COPY --from=builder /code/dist/gordo-components-packed.tar.gz .
-
-RUN pip install ./gordo-components-packed.tar.gz
-
 CMD ["build"]

Dockerfile-ModelServer

@@ -16,6 +16,7 @@ FROM python:3.6.8-slim-stretch
 COPY requirements.txt /code/
 RUN pip install -r /code/requirements.txt
 
+# Install gordo-components, packaged from earlier 'python setup.py sdist'
 COPY --from=builder /code/dist/gordo-components-packed.tar.gz .
 
 # Install gordo-components, packaged from earlier 'python setup.py sdist'