Add tests for when '-' is used to signify to use standard input #29

Job	Run time
cargo fmt --all -- --check	23s
cargo clippy -- -D warnings (ubuntu-latest)	16s
Code Coverage (ubuntu-latest, unix)	2m 16s
cargo clippy -- -D warnings (macOS-latest)	14s
cargo check (ubuntu-latest)	15s
GNU test suite	38s
Code Coverage (macos-latest, macos)	4m 6s
cargo clippy -- -D warnings (windows-latest)	49s
cargo check (macOS-latest)	22s
Code Coverage (windows-latest, windows)	59s
cargo check (windows-latest)	53s
cargo test (ubuntu-latest)	51s
cargo test (macOS-latest)	6m 12s
cargo test (windows-latest)	1m 9s
	19m 23s

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