(GNU options) - Implement `-v, --version`

[ghostsquad]

Related to #4 this issue is to add additional options that make sense:

Options: -b, --beep beep if command has a non-zero exit -c, --color interpret ANSI color and style sequences -d, --differences[=] highlight changes between updates -e, --errexit exit if command has a non-zero exit -g, --chgexit exit when output from command changes -n, --interval seconds to wait between updates -p, --precise attempt run command in precise intervals -t, --no-title turn off header -x, --exec pass command to exec instead of "sh -c"

-h, --help display this help and exit -v, --version output version information and exit

This issue is to implement the -v, --version option