Add CI build, closes #1

Reviewed-on: #2

.drone.yml

@@ -0,0 +1,13 @@
+---
+kind: pipeline
+type: docker
+name: default
+
+steps:
+  - name: build
+    image: python:3-alpine
+    commands:
+      - apk add gcompat
+      - ln -s /lib /lib64
+      - pip install platformio
+      - pio run

README.md

@@ -1,7 +1,11 @@
 # wifiscan
 
+[![Build Status][drone-badge]][drone]
+
 An ESP8266-based Wi-Fi scanner, which I use combined with [OsmAnd][osmand]'s
 GPX recording plugin and [Serial USB Terminal][usb] to log Wi-Fi APs on the go.
 
 [osmand]: https://f-droid.org/en/packages/net.osmand.plus/
 [usb]: https://play.google.com/store/apps/details?id=de.kai_morich.serial_usb_terminal
+[drone]: https://drone.tildegit.org/lucidiot/wifiscan
+[drone-badge]: https://drone.tildegit.org/api/badges/lucidiot/wifiscan/status.svg