MAINT: Rename master to main

.docker/Dockerfile

@@ -14,15 +14,15 @@ RUN apt-get update && \
      libxml2 \
 	 -y
 COPY .docker/wait-for-it.sh /wait-for-it.sh
-ADD https://gitlab.com/api/v4/projects/13656973/repository/branches/master \
+ADD https://gitlab.com/api/v4/projects/13656973/repository/branches/main \
    pylib_version.json
 RUN git clone https://gitlab.com/caosdb/caosdb-pylib.git && \
    cd caosdb-pylib && pip3 install .
-ADD https://gitlab.com/api/v4/projects/13656965/repository/branches/master \
+ADD https://gitlab.com/api/v4/projects/13656965/repository/branches/main \
    model_version.json
 RUN git clone https://gitlab.com/caosdb/caosdb-models.git && \
    cd caosdb-models && pip3 install .
-ADD https://gitlab.com/api/v4/projects/13601752/repository/branches/master \
+ADD https://gitlab.com/api/v4/projects/13601752/repository/branches/main \
    scifolder_version.json
 RUN git clone \
     https://gitlab.com/henrik_indiscale/scifolder.git && \