Update new docker build of demos structure

docker/Dockerfile

@@ -10,7 +10,7 @@ COPY ./src src
 
 RUN cd src/angular/frontend && \
 	npm install && \
-	./node_modules/@angular/cli/bin/ng build --output-path ../../main/resources/static
+	npx ng build --output-path ../../main/resources/static
 
 
 FROM maven:3.6.3 as backend-build

docker/create_image.sh

@@ -1,6 +1,9 @@
 #!/bin/bash
+if [ $# -eq 0 ]; then
+    echo "No version argument provided. Usage: \"./create_image.sh X.Y.Z\""
+    exit 1
+fi
+
 pushd ../
-export SOFTWARE_VERSION=$(grep -oPm1 "(?<=<version>)[^<]+" "pom.xml")
 
-docker build -f docker/Dockerfile -t openvidu/openvidu-classroom-demo .
-docker tag openvidu/openvidu-classroom-demo:latest openvidu/openvidu-classroom-demo:$SOFTWARE_VERSION
+docker build -f docker/Dockerfile -t openvidu/openvidu-classroom-demo:"${1}" .