build the Dockerimage used in CI

Dockerfile

@@ -11,5 +11,5 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
     && apt-get clean && \
     rm -rf /var/lib/apt/lists/*
 
-RUN conda env create -qf environment.yml
+RUN conda env update -n root -f environment.yml
 RUN pip install -r test-requirements.txt