Update version in Cargo.toml

Skip sequences shorter than 4 nucleotides

Fix rust toolchain version

Add the ORF extraction function to lib.rs

Merge pull request #5 from apcamargo/parallel-kmers

Parallelize k-mer frequency computation

Merge pull request #4 from apcamargo/rust-kmers

Version 0.2.0

Bump to 0.1.6

Merge pull request #3 from apcamargo/new-cli

New CLI format

Change URL in setup.py

Add a MANIFEST.in file