Update Docker file to use scipopt channel

Author: AntoinePrv

.circleci/Dockerfile

@@ -1,29 +1,10 @@
-FROM continuumio/miniconda AS scip-builder
-
-ENV CONDA_BLD_PATH /opt/scipoptsuite/channel
-WORKDIR /opt/scipoptsuite
-
-ARG scipoptsuite_url
-COPY recipe recipe
-
-RUN conda install conda-build conda-verify
-
-RUN wget -q "${scipoptsuite_url:?}"
-RUN tar -xzf scipoptsuite-7.0.0.tgz
-RUN SCIP_DIR="${PWD}/scipoptsuite-7.0.0" conda build -c conda-forge recipe/scipoptsuite-7.0.0
-RUN conda build -c file://${CONDA_BLD_PATH} -c conda-forge recipe/pyscipopt
-
-
 FROM continuumio/miniconda
 
-ENV SCIP_CHANNEL /opt/scipoptsuite/channel
-COPY --from=scip-builder ${SCIP_CHANNEL} ${SCIP_CHANNEL}
-
 RUN for PY_VERSION in "3.6" "3.7" "3.8" ; do \
 		conda create -n "ecole-py${PY_VERSION:?}" \
-			--use-local -c file://${SCIP_CHANNEL} -c conda-forge  \
+			--channel scipopt --channel conda-forge  \
 			gxx_linux-64 clangxx cmake'>=3.15' make conan clang-tools'>=10' \
-			scipoptsuite pyscipopt python="${PY_VERSION:?}" pybind11 xtensor-python numpy \
+			scip pyscipopt'>=3.0.1' python="${PY_VERSION:?}" pybind11 xtensor-python numpy \
 			pytest pytest-benchmark black \
 			doxygen sphinx'>=3.0' breathe'>=4.15' sphinx_rtd_theme ; \
 	done && \