Issue Parsing Positive Time Zone Offset (+07:00) in @std/toml

[immccn123]

Describe the bug

Date strings like 1979-05-27T00:32:00+07:00 is not parsed.

According to the TOML Spec, RFC 3339 formatted date-time with offset should be parsed.

Steps to Reproduce

import * as toml from "@std/toml";

toml.parse("time = 1979-05-27T00:32:00-07:00") // ok
toml.parse("time = 1979-05-27T00:32:00+07:00") // not ok
//                                    ^

Then

error: Uncaught (in promise) SyntaxError: Parse error on line 1, column 26: Unexpected character: "+"
      throw new SyntaxError(message);
            ^
    at https://jsr.io/@std/toml/1.0.1/_parser.ts:801:13
    at Module.parse (https://jsr.io/@std/toml/1.0.1/parse.ts:26:24)
    at index.ts:4:6

Expected behavior

Both negative and positive time zone offsets (-07:00 and +07:00) should be parsed correctly.

Environment

• OS: Ubuntu 20.04
• deno version: 1.43.6
• std version: jsr:@std/toml@^1.0.1