Update goreleaser config to work with latest version

.gitignore

@@ -4,3 +4,4 @@ acme-dns.log
 .vagrant
 coverage.out
 .idea/
+dist/

.goreleaser.yml

@@ -5,17 +5,17 @@ builds:
     goos:
       - linux
     goarch:
-      - 386
       - amd64
 
-archive:
+archives:
-  format: tar.gz
+  - id: tgz
-  files:
+    format: tar.gz
-    - LICENSE
+    files:
-    - README.md
+      - LICENSE
-    - Dockerfile
+      - README.md
-    - config.cfg
+      - Dockerfile
-    - acme-dns.service
+      - config.cfg
+      - acme-dns.service
 
-sign:
+signs:
-  artifacts: checksum
+  - artifacts: checksum