update CIs to Go 1.12

.circleci/config.yml

@@ -44,6 +44,6 @@ workflows:
   workflow:
     jobs:
       - build:
-          name: "Go 1.12rc1"
-          image: "circleci/golang:1.12rc1"
+          name: "Go 1.12"
+          image: "circleci/golang:1.12"
           runrace: true

.travis.yml

@@ -4,7 +4,7 @@ group: travis_latest
 language: go
 
 go:
-  - "1.12rc1"
+  - "1.12.x"
 
 # first part of the GOARCH workaround
 # setting the GOARCH directly doesn't work, since the value will be overwritten later

appveyor.yml

@@ -14,8 +14,8 @@ clone_folder: c:\gopath\src\github.com\lucas-clemente\quic-go
 
 install:
   - rmdir c:\go /s /q
-  - appveyor DownloadFile https://storage.googleapis.com/golang/go1.12rc1.windows-amd64.zip
-  - 7z x go1.12rc1.windows-amd64.zip -y -oC:\ > NUL
+  - appveyor DownloadFile https://storage.googleapis.com/golang/go1.12.windows-amd64.zip
+  - 7z x go1.12.windows-amd64.zip -y -oC:\ > NUL
   - set PATH=%PATH%;%GOPATH%\bin\windows_%GOARCH%;%GOPATH%\bin
   - echo %PATH%
   - echo %GOPATH%