assert2 0.1.0

assert!(...) and check!(...) macros inspired by Catch2
Documentation
v0.1.0:
  * Fully compatible with Rust stable.
  * Only use `proc_macro_span` on nightly.
  * Tweak colors in output.

v0.0.9:
  * Use `proc-macro-hack` to avoid `feature(proc_macro_hygiene)`.
  * Use auto-deref specialization to avoid `feature(proc_macro_hygiene)`.

v0.0.8:
  * Fix compilation error in assert!()
  * Limit scope of generated temporary variables

v0.0.7:
  * Update documentation.

v0.0.6:
  * Support additional arguments to print custom messages with failures.

v0.0.5:
  * Update documentation.
  * Fix images in documentation.

v0.0.4:
  * Support pattern matching with `let` expressions in assertions.