Extract billy (#173)

* Extract billy

Billy is a new library directly extracted from go-git. It abstract
several storages systems in a filesystem interface.

More in github.com/src-d/billy

* Fix grouping in imports block

* Update billy to v1

* Re-remove fs_implementation example

1 files changed, 0 insertions, 52 deletions

diff --git a/utils/fs/fs.go b/utils/fs/fs.go
deleted file mode 100644
index 7e6c01f..0000000
--- a/utils/fs/fs.go
+++ /dev/null
@@ -1,52 +0,0 @@
-// Package fs interace and implementations used by storage/filesystem
-package fs
-
-import (
-	"errors"
-	"io"
-	"os"
-)
-
-var (
-	ErrClosed       = errors.New("file: Writing on closed file.")
-	ErrReadOnly     = errors.New("this is a read-only filesystem")
-	ErrNotSupported = errors.New("feature not supported")
-)
-
-type Filesystem interface {
-	Create(filename string) (File, error)
-	Open(filename string) (File, error)
-	OpenFile(filename string, flag int, perm os.FileMode) (File, error)
-	Stat(filename string) (FileInfo, error)
-	ReadDir(path string) ([]FileInfo, error)
-	TempFile(dir, prefix string) (File, error)
-	Rename(from, to string) error
-	Remove(filename string) error
-	Join(elem ...string) string
-	Dir(path string) Filesystem
-	Base() string
-}
-
-type File interface {
-	Filename() string
-	IsClosed() bool
-	io.Writer
-	io.Reader
-	io.Seeker
-	io.Closer
-}
-
-type FileInfo os.FileInfo
-
-type BaseFile struct {
-	BaseFilename string
-	Closed       bool
-}
-
-func (f *BaseFile) Filename() string {
-	return f.BaseFilename
-}
-
-func (f *BaseFile) IsClosed() bool {
-	return f.Closed
-}