Merge branch 'TMSS-291' into 'master'

TMSS-291: Fix Django version to prevent import errors on DRF

Closes TMSS-291

See merge request !189

Docker/lofar-ci/Dockerfile_ci_sas

@@ -16,7 +16,7 @@ RUN yum erase -y postgresql postgresql-server postgresql-devel && \
     cd /bin && ln -s /usr/pgsql-9.6/bin/initdb && ln -s /usr/pgsql-9.6/bin/postgres
 ENV PATH /usr/pgsql-9.6/bin:$PATH 
 
-RUN pip3 install cython kombu lxml requests pygcn xmljson mysql-connector-python python-dateutil django djangorestframework djangorestframework-xml ldap==1.0.2 flask fabric coverage python-qpid-proton PyGreSQL numpy h5py psycopg2 testing.postgresql Flask-Testing scipy Markdown django-filter python-ldap python-ldap-test ldap3 djangorestframework django-jsonforms django-json-widget django-jsoneditor drf-yasg flex swagger-spec-validator django-auth-ldap mozilla-django-oidc jsonschema comet
+RUN pip3 install cython kombu lxml requests pygcn xmljson mysql-connector-python python-dateutil Django==3.0.9 djangorestframework djangorestframework-xml ldap==1.0.2 flask fabric coverage python-qpid-proton PyGreSQL numpy h5py psycopg2 testing.postgresql Flask-Testing scipy Markdown django-filter python-ldap python-ldap-test ldap3 djangorestframework django-jsonforms django-json-widget django-jsoneditor drf-yasg flex swagger-spec-validator django-auth-ldap mozilla-django-oidc jsonschema comet
 
 
 # Note: nodejs now comes with npm, do not install the npm package separately, since that will be taken from the epel repo and is conflicting.