V0.5.2 Fix create SSH key issue

This is a hotfix for creating SSH key issue.

V0.5.1 Display SSH public key by alias name

Now you can display SSH public key by specific alias name:

% skm display prod

V0.5 Add description to SSH keys

Display SSH keys for command skm ls.

• Related issue: #12
• Related pull requests: #19 #20

V0.4 with prompt UI

Add prompt UI for skm use command, please refer to: https://github.com/TimothyYe/skm#prompt-ui-for-key-selection

V0.3.4 with hook mechanism

Edit and place a executable file named hook at the specified key directory, for example:

~/.skm/prod/hook

This hook file can be both an executable binary file or an executable script file.
SKM will call this hook file after switching default SSH key to it, you can do some stuff in this hook file.

V0.3.3 add copy command

Now you can copy SSH public key to a remote host using "copy" command

V0.3.2 with minor issue fixed

Fix issue #5 - Empty skm directory causing skm init to fail

V0.3.1 with bugs fixed

• With bugs fixed
• Optimize code struct

V0.3 add rename command

Add rename command, support to rename SSH key alias name to a new one.

V0.2.1 with minor issue fixed

for release V0.2.1