Move all error structs to common package 'errors'

Change-Id: I91e9610b27244fe5d7500575eae24647e256dab8

pkg/error/error.go

@@ -1,14 +0,0 @@
-package error
-
-// AirshipError is the base error type
-// used to create extended error types
-// in other airshipctl packages.
-type AirshipError struct {
-	Message string
-}
-
-// Error function implments the golang
-// error interface
-func (ae *AirshipError) Error() string {
-	return ae.Message
-}

pkg/errors/common.go

@@ -1,5 +1,18 @@
 package errors
 
+// AirshipError is the base error type
+// used to create extended error types
+// in other airshipctl packages.
+type AirshipError struct {
+	Message string
+}
+
+// Error function implments the golang
+// error interface
+func (ae *AirshipError) Error() string {
+	return ae.Message
+}
+
 // ErrNotImplemented returned for not implemented features
 type ErrNotImplemented struct {
 }

pkg/remote/errors.go

@@ -3,7 +3,7 @@ package remote
 import (
 	"fmt"
 
-	aerror "opendev.org/airship/airshipctl/pkg/error"
+	aerror "opendev.org/airship/airshipctl/pkg/errors"
 )
 
 type RemoteDirectError struct {

pkg/remote/redfish/errors.go

@@ -4,7 +4,7 @@ import (
 	"fmt"
 	"net/http"
 
-	aerror "opendev.org/airship/airshipctl/pkg/error"
+	aerror "opendev.org/airship/airshipctl/pkg/errors"
 )
 
 type RedfishClientError struct {