Update Dockerfile

Dockerfile

@@ -9,7 +9,7 @@ RUN apt-get update && apt-get install -y libgl1-mesa-glx libosmesa6
 RUN apt-get install -y python3-opengl
 RUN apt-get install -y libosmesa6-dev
 RUN apt-get install -y freeglut3-dev
-RUN apt-get install xvfb xserver-xephyr tigervnc-standalone-server x11-utils gnumeric
+RUN apt-get install -y xvfb xserver-xephyr tigervnc-standalone-server x11-utils gnumeric
 # RUN apt update && apt install -y python3 python3-pip git xvfb xorg-dev cmake
 RUN apt-get upgrade -y && apt-get install -y python3-pip python-is-python3 && rm -rf /var/lib/apt/lists/* 
 RUN pip install -r requirements.txt