Allow numbers in keys parsing

token.go

@@ -120,7 +120,7 @@ func isKeyChar(r rune) bool {
 	// Keys start with the first character that isn't whitespace or [ and end
 	// with the last non-whitespace character before the equals sign. Keys
 	// cannot contain a # character."
-	return !(isSpace(r) || r == '\r' || r == '\n' || r == eof || r == '=')
+	return !(r == '\r' || r == '\n' || r == eof || r == '=')
 }
 
 func isKeyStartChar(r rune) bool {