readme: lastpass-cli is available using homebrew

Signed-off-by: Stian Eikeland <stian@eikeland.se>
Merge branch 'stianeikeland-brew'
remove "All Rights Reserved" language

'All Rights Reserved' is not necessary to assert copyright and
can be confusing as this work is under the GPL license.

Signed-off-by: Bob Copeland <copeland@lastpass.com>
Merge remote-tracking branch 'upstream/master'