message: changelog: prepare for 1.3 release
diff: -UNRELEASED
  -==========
  +1.3.0 (2019-09-02)
  +==================
  +This release adds a plethora of new crate features that permit users of regex
  +to shrink its size considerably, in exchange for giving up either functionality
  +(such as Unicode support) or runtime performance. When all such features are
  +disabled, the dependency tree for `regex` shrinks to exactly 1 crate
  +(`regex-syntax`). More information about the new crate features can be
  +[found in the docs](https://docs.rs/regex/*/#crate-features).
  +
  +Note that while this is a new minor version release, the minimum supported
  +Rust version for this crate remains at `1.28.0`.
  New features:
  @@ -7,6 +16,8 @@ New features:
  The `use_std` feature has been deprecated in favor of the `std` feature.
  The `use_std` feature will be removed in regex 2. Until then, `use_std` will
  remain as an alias for the `std` feature.
  +* [FEATURE #583](https://github.com/rust-lang/regex/issues/583):
  + Add a substantial number of crate features shrinking `regex`.
  1.2.1 (2019-08-03)
  