Fix to handle subdomain as git-commit-id inside pool

- Fix hook.rb and build_server not to create another container
  if the same commit-id is given so that it targets the same container
  if it gets branch name or tag.
- Fix Dockerfile to test builder gem while building the container
- Modified application's repository path is on fixed path; `app_repo`
- Refactor hook.rb
Merge pull request #61 from mookjp/issue-33_see-actual-commit-id

#33 Fix to see actual git-commit-id if branch or tag name was given
Add deployment scripts; WIP

- Add ansible scripts to install Docker into Ubuntu machine. This
  deployment scripts needs to install Ansible by pip

Follow below command to execute:
```sh
export AWS_ACCESS_KEY_ID=<KEY>
export AWS_SECRET_KEY=<KEY>
ansible-galaxy install angstwad.docker_ubuntu --roles-path=./roles
export EC2_INI_PATH=./ec2.ini; ansible-playbook --private-key <Path>\
-i ec2.py --sudo -u ubuntu -U root playbook.yml
```
WIP: add task to create container