Improve build of container

Each time the scripts were changed all dependencies had to be
re-downloaded, thereby greatly increasing the build time.

This change optimizes the build process. Dependencies now are not
downloaded, if only the scripts changed, making the build more efficient
during development.

Change-Id: If02df80493edb1a545e7d819f8c5bdf50318dbe6
diff --git a/container/Dockerfile b/container/Dockerfile
index bf7ac13..31738ea 100644
--- a/container/Dockerfile
+++ b/container/Dockerfile
@@ -5,11 +5,13 @@
 ENV LC_ALL=C.UTF-8
 ENV LANG=C.UTF-8
 
-COPY tools/ ./
-
 RUN apk --no-cache --update-cache add git gcc gfortran build-base
 
+COPY dependencies/ ./
+
 RUN pip3 install --no-cache --upgrade pipenv && \
     pipenv install --python 3.7.3 --system
 
+COPY tools/ ./
+
 ENTRYPOINT [ "python3", "./start_test.py" ]
diff --git a/container/tools/Pipfile b/container/dependencies/Pipfile
similarity index 100%
rename from container/tools/Pipfile
rename to container/dependencies/Pipfile
diff --git a/container/tools/Pipfile.lock b/container/dependencies/Pipfile.lock
similarity index 100%
rename from container/tools/Pipfile.lock
rename to container/dependencies/Pipfile.lock