You are trying to view this URL with a browser, while it is meant to serve a YAML file directly to your 'oc' or 'kubectl' program.

Please try this on your commandline: 
curl --fail --location 'http://goroom.blum.coffee/ocp?gitBranch=gh-pages&gitSource=https%3A%2F%2Fgithub.com%2Fred-hat-storage%2Focs-training.git&namespace=default' | oc apply -f -
or the same with kubectl: 
curl --fail --location 'http://goroom.blum.coffee/ocp?gitBranch=gh-pages&gitSource=https%3A%2F%2Fgithub.com%2Fred-hat-storage%2Focs-training.git&namespace=default' | kubectl apply -f -

###
# Code generated by goroom.blum.coffee
# This can be used directly with "oc apply -f" or "kubectl apply -f"
#   to deploy a goroom environment
###


apiVersion: v1
kind: Namespace
metadata:
  name: default
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: goroom-role
  namespace: default
---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: goroom-role-binding
subjects:
  - kind: ServiceAccount
    name: goroom-role
    namespace: default
roleRef:
  kind: ClusterRole
  name: cluster-admin
  apiGroup: rbac.authorization.k8s.io
---
apiVersion: v1
kind: Service
metadata:
  name: goroom-app
  namespace: default
  labels:
    app: goroom-app
spec:
  # type: NodePort
  ports:
    - port: 8080
      name: goroom-app
  selector:
    app: goroom-app
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: goroom-app
  namespace: default
  labels:
    app: goroom-app
spec:
  replicas: 1
  selector:
    matchLabels:
      app: goroom-app
  template:
    metadata:
      labels:
        app: goroom-app
    spec:
      serviceAccountName: goroom-role
      initContainers:
        - name: goroom-init
          image: quay.io/mulbc/goroom-init
          volumeMounts:
            - name: goroom-content
              mountPath: /content
          env:
            - name: GIT_SOURCE
              value: https://github.com/red-hat-storage/ocs-training.git
            - name: GIT_BRANCH
              value: gh-pages
      containers:
        - name: goroom-app
          image: quay.io/mulbc/goroom
          volumeMounts:
            - name: goroom-content
              mountPath: /app/content
          livenessProbe:
            httpGet:
              path: /ping
              port: 8080
            periodSeconds: 100
          ports:
            - containerPort: 8080
        - name: gotty
          image: quay.io/mulbc/gotty
          livenessProbe:
            httpGet:
              path: /ping
              port: 8081
            periodSeconds: 100
          env:
            - name: GOTTY_ADDRESS
              value: "0.0.0.0"
            - name: GOTTY_PORT
              value: "8081"
            - name: GOTTY_WS_ORIGIN
              value: ".*"
          ports:
            - containerPort: 8081
      volumes:
        - name: goroom-content
          emptyDir: {}
---
apiVersion: route.openshift.io/v1
kind: Route
metadata:
  name: goroom
  namespace: default
spec:
  tls:
    termination: edge # Use OCP cert
    insecureEdgeTerminationPolicy: Redirect
  to:
    kind: Service
    name: goroom-app
  port:
    targetPort: goroom-app