QR code generation via cli

Added flag -qr for a generation of qr code

Signature and verification

Added support of signature/verification messages and files.

Added wrap errors of commands

Thanks @marti1125 for the wrapping errors #23

QR code generation

v0.1.9

Bumped version

Minor fixes

v0.1.8

Bumped version. Minor fixes and small refactoring in API implementation

Encryption from browser

Added fixes for ephemeral-decrypt from browser

HTTP server

Added serve http.
Added connect to mongodb with TLS certs

Added link flag for upload/download ecnrypted data to server

Added --link flag for all encrypt commands.
Added --link flag for all decrypt commands
Added support method in POST data to pspk.now.sh
Added GET data by link from pspk.now.sh

Small fixes

Updated pspk cli usage.

Added check limit name of key

• Added check limit name of key to cli tool.
• Added check limit name of key to http-lambda.