Migrate the openssl-sys crate to the 2018 edition

#![allow(clippy::uninlined_format_args)]

use proc_macro::TokenStream;

use proc_macro2::Ident;

use quote::quote;

categories = ["cryptography", "external-ffi-bindings"]

links = "openssl"

build = "build/main.rs"

edition = "2018"

[features]

vendored = ['openssl-src']

use pkg_config;

use std::ffi::OsString;

use std::path::{Path, PathBuf};

use std::process::{self, Command};

#![allow(clippy::inconsistent_digit_grouping, clippy::unusual_byte_groupings)]

#![allow(

    clippy::inconsistent_digit_grouping,

    clippy::uninlined_format_args,

    clippy::unusual_byte_groupings

)]

extern crate autocfg;

#[cfg(feature = "bindgen")]

use libc::*;

use *;

use super::*;

// ASN.1 tag values

pub const V_ASN1_EOC: c_int = 0;