Exit client after successful unlocking

Closes #26

See merge request !26

Update readme to mention dependencies

Closes #28

See merge request !28

Add command for selfdestruct

Closes #25

See merge request !25

Resolve "Debug command"

Closes #24

See merge request !24

Add a function for running jq

Closes #23

See merge request !23

Add command for removing encryption key

Closes #22

See merge request !22

Also warn in the help text that removing encryption keys can be
dangerous.

Resolve "Weird terminal behaviour when ssh command is given"

Closes #12

See merge request !21

use jq to parse/prettify JSON output

Closes #19

See merge request !20

The behaviour of SSH_ORIGINAL_COMMAND is too unpredictable in the context of
this sh script, because it seems to modify the flow of strings to stdout/stderr.
After a discussion with @arie we decided to remove this functionality from the
script.

The alternative would have been to make a non-interactive version of the script
that could be used for running 1 command immediately, but that would require us
to change the code so much that it would become too cluttered. Apart from that,
this feature would serve the same goal as the cryptops-api is serving, so
supporting remote access to the cryptops-api would be a lot better use of our
time.

Add command for adding encryption key

Closes #21

See merge request !19

Add command for listing encryption keys

Closes #20

See merge request !18

Resolve "Add command for ssh/keys/{put,delete}"

Closes #18

See merge request !17

cryptops-client hook for ssh-keys-add

Closes #17

See merge request !16

Pass the request body to curl via its stdin, circumventing some
shell escaping problems.

Also replace `echo` by `printf` when piping strings as input to commands.

Add command for removing encryption

Closes #14

See merge request !15