Add Woodpeck CI config (#5)

Closes kemitix/paperoni#3

Reviewed-on: #5
Co-authored-by: Paul Campbell <pcampbell@kemitix.net>
Co-committed-by: Paul Campbell <pcampbell@kemitix.net>

.woodpecker.yml

@@ -0,0 +1,20 @@
+steps:
+  build:
+    when:
+      - event: cron
+      - event: push
+        branch: main
+      - event: pull_request
+    image: docker.io/rust:1.52.1
+    commands:
+      - apt-get install libssl-dev
+      - cargo build
+  test:
+    when:
+      - event: cron
+      - event: push
+        branch: main
+      - event: pull_request
+    image: docker.io/rust:1.52.1
+    commands:
+      - cargo test