add gcc to docker

Dockerfile

@@ -2,6 +2,9 @@ FROM nfcore/base
 LABEL authors="Nicolas Servant" \
       description="Docker image containing all requirements for nf-core/hic pipeline"
 
+## Install gcc for pip CellProfiler install
+RUN apt-get update && apt-get install -y gcc g++ && apt-get clean -y
+
 COPY environment.yml /
 RUN conda env create -f /environment.yml && conda clean -a
 ENV PATH /opt/conda/envs/nf-core-hic-1.0dev/bin:$PATH