remove custom gitpod as the default one is good enough and faster

.gitpod

@@ -1,4 +1,2 @@
-image:
-  file: .gitpod.DockerFile
 tasks:
 - command: npm install

.gitpod.DockerFile

@@ -1,24 +0,0 @@
-FROM node:14
-
-# Install OpenJDK-8
-RUN apt-get update && \
-    apt-get install -y openjdk-8-jdk && \
-    apt-get install -y ant && \
-    apt-get clean;
-
-# Fix certificate issues
-RUN apt-get update && \
-    apt-get install ca-certificates-java && \
-    apt-get clean && \
-    update-ca-certificates -f;
-
-# Setup JAVA_HOME -- useful for docker commandline
-ENV JAVA_HOME /usr/lib/jvm/java-8-openjdk-amd64/
-RUN export JAVA_HOME
-
-RUN apt-get update &&  apt-get -y install xvfb gconf-service libasound2 libatk1.0-0 libc6 libcairo2 libcups2 \
-      libdbus-1-3 libexpat1 libfontconfig1 libgbm1 libgcc1 libgconf-2-4 libgdk-pixbuf2.0-0 libglib2.0-0 \
-      libgtk-3-0 libnspr4 libpango-1.0-0 libpangocairo-1.0-0 libstdc++6 libx11-6 libx11-xcb1 libxcb1 \
-      libxcomposite1 libxcursor1 libxdamage1 libxext6 libxfixes3 libxi6 libxrandr2 libxrender1 libxss1 \
-      libxtst6 ca-certificates fonts-liberation libappindicator1 libnss3 lsb-release xdg-utils wget && \
-    rm -rf /var/lib/apt/lists/*