[skip changelog] better match for skip clauses (#449)

Author: Massimiliano Pippi

Diff for: .goreleaser.yml

@@ -11,10 +11,10 @@ release:
 changelog:
   filters:
     exclude:
-      - '^\[skip changelog\].*'
-      - '^\[changelog skip\].*'
-      - '^\[skip ci\].*'
-      - '^\[ci skip\].*'
+      # [skip changelog], [skip-changelog], [changelog skip], [changelog-skip]
+      - '^(?i)\[(skip|changelog)[ ,-](skip|changelog)\].*'
+      # [skip ci], [skip-ci], [ci skip], [ci-skip]
+      - '^(?i)\[(skip|ci)[ ,-](skip|ci)\].*'
 
 # We have multiple builds in order to fine tune
 # cross compilations.

Diff for: go.mod

@@ -43,6 +43,7 @@ require (
 	go.bug.st/serial.v1 v0.0.0-20180827123349-5f7892a7bb45
 	golang.org/x/net v0.0.0-20190311183353-d8887717615a
 	golang.org/x/text v0.3.0
+	google.golang.org/appengine v1.4.0 // indirect
 	google.golang.org/genproto v0.0.0-20190327125643-d831d65fe17d // indirect
 	google.golang.org/grpc v1.21.1
 	gopkg.in/mgo.v2 v2.0.0-20180705113604-9856a29383ce // indirect