Add endpoint for adding encryption key

Closes #5

See merge request !14

Replace the very similar encryption_keys_post and encryption_keys_put
callback functions by a single handler function, with a boolean flag to
separate the two variants.

Add endpoint for listing encryption keys

Closes #4

See merge request !13

Resolve "Delete ssh-key endpoint"

Closes #9

See merge request !12

Add endpoint for removing encryption

Closes #10

See merge request !11

basic PUT and DELETE behavior, still does some weird stuff with random unicode characters appearing some times

use /cryptops-api instead of /test in Vagrantfile and deploy script. Also mount cryptops-client directory if it exists

Add endpoint for showing encryption status

Closes #18

See merge request !9

Update the new endpoint for removing encryption to follow some other
changes: adding the http method to callback names, and renaming of
device path constants.

In case the device is unencrypted, check whether encryption seems
possible (depending on filesystem usage and available memory), and
report that in the response.

Sleep for a bit after we received a signal to stop cryptops-api. This
gives the request handler that asked to stop the server more time to
send its response to the client, fixing a race condition.

Add endpoint for changing encryption passwords

Closes #5

See merge request !8