ppar 0.3.1

Persistent immutable array
Documentation
0.3.1
=====

* replace `assert!()` calls with `debug_assert!()`
* improvise check.sh and perf.sh
* reduce time taken to run unit test cases.
* clippy fixes
* rustdoc

0.3.0
=====

* Rustdoc
* rust-fmt fix column width to 90.
* move bin/fuzzy.rs to unit test `fuzzy_test.rs`.
* clippy fixes.
* modularize bin/perf.rs for ppar, im and std-vec benchmarks.
* package management files and ci-scripts.

Refer to [release-checklist][release-checklist].

[release-checklist]: https://prataprc.github.io/rust-crates-release-checklist.html