Restructure project directories

Follow the standard of all go projects

config/errors.go

@@ -1,25 +0,0 @@
-package config
-
-import (
-	"fmt"
-	"strconv"
-	"strings"
-)
-
-const (
-	errNoCommand             = "at least one command must be specified, use help to get commands"
-	errNotSupportedType      = "not supported configuration type"
-	errMissingWorkspaceField = "missing required \"workspace\" field"
-	errMissingSrcField       = "missing required field the \"src\" in row %v"
-	errNameAndTagsTogether   = "name and tags arguments connot be used together"
-)
-
-func getDuplicateFieldError(field string, name string, rows []int) error {
-
-	var rowsInString []string
-	for _, row := range rows {
-		rowsInString = append(rowsInString, strconv.Itoa(row))
-	}
-
-	return fmt.Errorf("the %v \"%v\" is duplicated in rows: %v", field, name, strings.Join(rowsInString, ","))
-}