Add dockerfile and ci config

Dockerfile

@@ -0,0 +1,22 @@
+FROM ubuntu:22.04
+
+ARG CHANNEL=stable
+
+RUN apt update
+RUN apt install -y curl git wget unzip
+RUN apt clean
+    # download Flutter SDK from Flutter Github repo \
+RUN git clone -b ${CHANNEL} https://github.com/flutter/flutter.git /usr/local/flutter
+
+# Set flutter environment path
+ENV PATH="/usr/local/flutter/bin:/usr/local/flutter/bin/cache/dart-sdk/bin:${PATH}"
+
+RUN flutter doctor
+
+# Propably not needed since we clone that branch above, but to be sure
+RUN flutter channel ${CHANNEL}
+RUN flutter config --enable-web
+
+RUN flutter upgrade
+RUN flutter precache
+RUN flutter --version