switch from exportloopref to copyloopvar

Author: JakeChampion

.golangci.yml

@@ -9,7 +9,7 @@ linters:
   enable:
     - durationcheck
     - errcheck
-    - exportloopref
+    - copyloopvar
     - forcetypeassert
     - godot
     - gofmt
@@ -24,4 +24,4 @@ linters:
     - unconvert
     - unparam
     - unused
-    - vet
+    - vet