ci: add Lint check on commits (#1086)

* ci: add Lint check on commits

* ci: fix Lint script error

* test: fix go vet errors

* test: fix go vet errors, remove gofumpt to check go vet

* test: fix go vet errors, try gofumpt

* test: fix go vet errors, try gofumpt, round 1

* test: fix go vet errors, try gofumpt, round 2

* ci: fix Lint errors

core/stores/mongo/internal/collection_mock.go

@@ -5,9 +5,10 @@
 package internal
 
 import (
+	reflect "reflect"
+
 	mgo "github.com/globalsign/mgo"
 	gomock "github.com/golang/mock/gomock"
-	reflect "reflect"
 )
 
 // MockMgoCollection is a mock of MgoCollection interface

core/stores/mongo/iter_mock.go

@@ -5,9 +5,10 @@
 package mongo
 
 import (
+	reflect "reflect"
+
 	bson "github.com/globalsign/mgo/bson"
 	gomock "github.com/golang/mock/gomock"
-	reflect "reflect"
 )
 
 // MockIter is a mock of Iter interface