Add build/install/test options in makefile

[c-goosen]

• Add Makefile
• Update Authors
• Readme updates

[singe]

Thank you Christo!

Some changes please:

1. Can you change the Makefile's build to use cargo build --release to generate release rather than debug builds.
2. On my install cargo install --path . installed to /Users/<user>/.cargo/bin/singrep it would be good to make the clear in the README.
3. Please put installation instructions in the README under a heading "Installation", and make the specific install steps sub headings (##).
4. Please add a clean directive to the Makefile with cargo clean

Some questions:

1. Why are you using CARGO_NET_GIT_FETCH_WITH_CLI I'm not aware of any special authentication requirements?
2. What is the purpose of the 'libc' in the cargo run directive? libc is included as a crate.