0.4.9: add test interface

Update gitbook:

1. update version to 0.4.8
2. add test_config to doc
3. add doc for developer
4. update changelog to 0.4.8

Update imageAPI:

1. add target 'test_config'
2. add target 'test_start'
3. add target 'test_stop'
4. add target 'test_restart'
5. add target 'test_remove'

0.4.7: update

Update gitbook:

1. update dependency: 1) add python and pyyaml
2. update deployment: 1) add step on title 2) replace 'service' to 'instance' 3) replace 'structure' to 'mode' 4) add imageAPI to directory and package 5) add configuration explanation
3. update confgen: 1) replace 'conf-generator' to 'confgenerator' 2) add new confgenerator usage 3) add validation 4) add 'step' on title
4. update summary: 1) add changelog document
5. add changelog

Update imageAPI:

1. only show the last 100 line of log when checking status
2. new config structure
3. stay true when checking status

Update makefile:

1. rename sskcp-server-x86 to sskcp-server-imageAPI-x86
2. rename sskcp-client-x86 to sskcp-client-imageAPI-x86
3. rename sskcp-client-armv6 to sskcp-client-imageAPI-armv6
4. rename confgenerator zip package name to sskcp-confgenerator-[version].zip

update confgenerator

1. cover the situation : if configuration exist
2. add some hint when script run
3. remove key 'dest' in conf-info
4. fix typo of template log path
5. update all mode to 'sskcp'
6. rename directory confgenerator to sskcp-confgenerator

update .gitignore:

1. ignore vscode setting