message: Have Ion support both dev and nightly builds of Rust
diff: @@ -2,7 +2,7 @@ extern crate ansi_term;
  extern crate version_check;
  use ansi_term::Color::{Blue, Red, White};
  -use version_check::is_nightly;
  +use version_check::supports_features;
  // Specifies the minimum version needed to compile Ion.
  // NOTE: 1.19 is required due to the usage of `break` with values for
  @@ -14,20 +14,20 @@ use std::{
  };
  fn main() {
  - match is_nightly() {
  + match supports_features() {
  Some(true) => (), // Success!
  Some(false) => {
  eprintln!(
  "{} {}",
  Red.bold().paint("Error:"),
  - White.paint("Ion requires nightly to build.")
  + White.paint("Ion requires nightly/dev to build.")
  );
  // print_version_err(&*version_string);
  eprintln!(
  "{}{}{}",
  Blue.paint("Use `"),
  White.paint("rustup update"),
  - Blue.paint("` to update to the latest stable compiler.")
  + Blue.paint("` to update to the latest nightly compiler.")
  );
  panic!("Aborting compilation due to incompatible compiler.")
  }
  