Congratulations on reaching the big 1.0! 
Congrats on the release!
I couldn't help but notice that the regex! macro is no longer present.
Is there a place where I can read up on why it was removed?
Didn't the regex!() macro use the old (nightly-only) syntax extensions method for generating the regex at compile time? If so, they probably deleted it to allow the addition of a regex!() using procedural macros when they stabilise.
Yes, it was removed last year. See: https://github.com/rust-lang/regex/blob/master/HACKING.md#the-regex-macro
Awesome! Thanks a lot for the awesome work with text in Rust 
I regularly use source code of the regex and related libraries in the local algorithms class to demonstrate how text book algorithms look like, when implemented for production usage!