Add drone

Signed-off-by: Jonas Franz <info@jonasfranz.de>

.drone.yml

@@ -0,0 +1,18 @@
+kind: pipeline
+name: default
+
+steps:
+- name: docker  
+  image: plugins/docker
+  settings:
+    repo: jonasfranz/flutter
+    build_args:
+      - FLUTTER_VERSION=2.2.1
+    tags:
+      - '2.2.1'
+      - '2'
+    username:
+      from_secret: docker_username
+    password:
+      from_secret: docker_password
+

Dockerfile

@@ -0,0 +1,5 @@
+ARG FLUTTER_VERSION
+FROM matspfeiffer/flutter:$FLUTTER_VERSION
+USER root:root
+RUN apt-get update && apt-get install -y build-essential
+