Switch from govendor to go modules. (#587)

Thanks to @BenoitKnecht for leading the way on this.

vendor/github.com/tdewolff/parse/buffer/writer.go

@@ -0,0 +1,41 @@
+package buffer // import "github.com/tdewolff/parse/buffer"
+
+// Writer implements an io.Writer over a byte slice.
+type Writer struct {
+	buf []byte
+}
+
+// NewWriter returns a new Writer for a given byte slice.
+func NewWriter(buf []byte) *Writer {
+	return &Writer{
+		buf: buf,
+	}
+}
+
+// Write writes bytes from the given byte slice and returns the number of bytes written and an error if occurred. When err != nil, n == 0.
+func (w *Writer) Write(b []byte) (int, error) {
+	n := len(b)
+	end := len(w.buf)
+	if end+n > cap(w.buf) {
+		buf := make([]byte, end, 2*cap(w.buf)+n)
+		copy(buf, w.buf)
+		w.buf = buf
+	}
+	w.buf = w.buf[:end+n]
+	return copy(w.buf[end:], b), nil
+}
+
+// Len returns the length of the underlying byte slice.
+func (w *Writer) Len() int {
+	return len(w.buf)
+}
+
+// Bytes returns the underlying byte slice.
+func (w *Writer) Bytes() []byte {
+	return w.buf
+}
+
+// Reset empties and reuses the current buffer. Subsequent writes will overwrite the buffer, so any reference to the underlying slice is invalidated after this call.
+func (w *Writer) Reset() {
+	w.buf = w.buf[:0]
+}