Add CI cache

.drone.yml

@@ -18,7 +18,7 @@ steps:
     image: docker.io/library/elixir:1.18.3-otp-27
     commands:
       - echo "$DRONE_REPO_OWNER/$DRONE_REPO_NAME" >> .cache_key
-      - echo $(sha256sum mix.lock) >> .cache_key
+      - echo $(sha256sum mix.lock | cut -d ' ' -f 1) >> .cache_key
       # Print cache key for debugging
       - cat .cache_key
 
@@ -32,7 +32,7 @@ steps:
       ttl: 30
     volumes:
       - name: cache
-        path: /tmp/cache
+        path: /cache
 
   - name: lint
     image: docker.io/library/elixir:1.18.3-otp-27
@@ -93,7 +93,7 @@ steps:
         - ./_build
     volumes:
       - name: cache
-        path: /tmp/cache
+        path: /cache
 
 volumes:
   - name: cache