Implement make_hostname

Signed-off-by: apporc <appleorchard2000@gmail.com>
Enable heat installation

Signed-off-by: apporc <appleorchard2000@gmail.com>
Use os.link to replace /usr/bin/cp command

Signed-off-by: apporc <appleorchard2000@gmail.com>
Fix os.link, need to chdir and delete file when file exists

Signed-off-by: apporc <appleorchard2000@gmail.com>
Update ntp server when needed

Signed-off-by: apporc <appleorchard2000@gmail.com>