chore: refactor dockerfile to use errors pkg

Signed-off-by: Justin Chadwell <me@jedevc.com>

ignorefile/ignorefile.go

@@ -3,10 +3,11 @@ package dockerignore
 import (
 	"bufio"
 	"bytes"
-	"fmt"
 	"io"
 	"path/filepath"
 	"strings"
+
+	"github.com/pkg/errors"
 )
 
 // ReadAll reads a .dockerignore file and returns the list of file patterns
@@ -58,7 +59,7 @@ func ReadAll(reader io.Reader) ([]string, error) {
 		excludes = append(excludes, pattern)
 	}
 	if err := scanner.Err(); err != nil {
-		return nil, fmt.Errorf("Error reading .dockerignore: %v", err)
+		return nil, errors.Wrap(err, "error reading .dockerignore")
 	}
 	return excludes, nil
 }