Load environment variables from .env file.
``` Usage: denv [OPTIONS] COMMAND...
Options: -f, --filename FILENAME Path to .env file -h, --help Print help ```
% cat .env
FOO=bar
% denv printenv FOO
bar
% cat hoge.env
HOGE=fuga
% denv -f printenv HOGE
fuga
rust
denv::load("/path/to/.env").expect("Unable to load .env file");
Original implementation is written by taiki45. https://github.com/taiki45/denv