fix Dockerfile

Dockerfile

@@ -3,8 +3,8 @@ ARG BASE_IMAGE=registry.git.rwth-aachen.de/jupyter/profiles/rwth-courses:2020-ss
 FROM ${BASE_IMAGE}
 
 # Install packages via requirements.txt
-ADD /tmp/requirement.txt .
-RUN pip3 install -r /tmp/requirements.txt
+ADD requirements.txt .
+RUN pip3 install -r requirements.txt
 
 # .. Or update conda base environment to match specifications in environment.yml
 ADD environment.yml /tmp/environment.yml