misc: require Go 1.12

License: MIT
Signed-off-by: Jakub Sztandera <kubuxu@protonmail.ch>

.circleci/config.yml

@@ -33,7 +33,7 @@ defaults: &defaults
     TRAVIS: 1
 
   docker:
-    - image: circleci/golang:1.11
+    - image: circleci/golang:1.12
 
 jobs:
   gotest:

go.mod

@@ -115,3 +115,5 @@ require (
 	gopkg.in/gemnasium/logrus-airbrake-hook.v2 v2.1.2 // indirect
 	gotest.tools/gotestsum v0.3.3
 )
+
+go 1.12

mk/golang.mk

 # golang utilities
-GO_MIN_VERSION = 1.11.4
+GO_MIN_VERSION = 1.12
 export GO111MODULE=on