TMSS-241: Fix npm issue in SAS CI docker

Docker/lofar-ci/Dockerfile_ci_sas

@@ -18,9 +18,13 @@ 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 npm install -g npx && \
-    npm install -g n && \
-    n stable && \
-    npm install -g serve
+# 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.
+RUN echo "Installing Nodejs packages..." && \
+    curl -sL https://rpm.nodesource.com/setup_14.x | bash - && \
+    yum install -y nodejs && \
+    npm -v && \
+    node -v && \
+    npm install -g serve && \
+    npm install -g npx
 
 USER lofarsys
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