Update rustfmt

Author: nhynes

rust/.rustfmt.toml

@@ -45,8 +45,7 @@ use_field_init_shorthand = false
 force_explicit_abi = true
 condense_wildcard_suffixes = false
 color = "Auto"
-required_version = "1.0.1"
-unstable_features = false
+unstable_features = true
 disable_all_formatting = false
 skip_children = false
 hide_parse_errors = false