Update Dockerfile

Dockerfile

@@ -22,7 +22,7 @@ COPY --chown=user . .
 RUN echo "-e ." > requirements.txt \
     && echo "flask" >> requirements.txt \
     && echo "flask_cors" >> requirements.txt \
-    && echo "yaml" >> requirements.txt \
+    && echo "PyYAML" >> requirements.txt \
     && echo "gunicorn" >> requirements.txt
 
 # Install Python dependencies