feat: improve gitInfo

[tyankatsu0105]

close #71

Be able to get some information from simple-git.

{
sha: undefined,
  abbreviatedSha: null,
  branch: 'master',
  tag: null,
  committer: null,
  committerDate: null,
  author: null,
  authorDate: null,
  commitMessage: null,
  root: '/Path/to/root',
  commonGitDir: '/Path/to/.git',
  worktreeGitDir: '/Path/to/.git',
  lastTag: null,
  commitsSinceLastTag: 0,

//below properties are new !!!
  not_added: [
    'test.txt'
  ],
  created: [ 'test.txt' ],
  deleted: [],
  modified: [],
  renamed: [],
  staged: []
}