Tidy up

- Ran goimports to format code and imports
- Removed unused module from go.mod
- Added .editorconfig to keep formatting standard across contributors

internal/pkg/node/modifiers.go

@@ -1,10 +1,11 @@
 package node
 
 import (
+	"os"
+
 	"github.com/hpcng/warewulf/internal/pkg/errors"
 	"github.com/hpcng/warewulf/internal/pkg/wwlog"
 	"gopkg.in/yaml.v2"
-	"os"
 )
 
 /****