Fix formatter configuration errors with latest nightly

rustfmt.toml

@@ -16,7 +16,6 @@ format_code_in_doc_comments = false
 comment_width = 80
 normalize_comments = false
 normalize_doc_attributes = false
-license_template_path = ""
 format_strings = false
 format_macro_matchers = false
 format_macro_bodies = true
@@ -53,7 +52,7 @@ trailing_comma = "Vertical"
 match_block_trailing_comma = false
 blank_lines_upper_bound = 1
 blank_lines_lower_bound = 0
-edition = "2015"
+edition = "2018"
 version = "One"
 inline_attribute_width = 0
 format_generated_files = true
@@ -63,15 +62,12 @@ use_field_init_shorthand = false
 force_explicit_abi = true
 condense_wildcard_suffixes = false
 color = "Auto"
-required_version = "1.4.38"
 unstable_features = false
 disable_all_formatting = false
 skip_children = false
 hide_parse_errors = false
 error_on_line_overflow = false
 error_on_unformatted = false
-report_todo = "Never"
-report_fixme = "Never"
 ignore = []
 emit_mode = "Files"
 make_backup = false