reimplement gita clone nosarthur#202 (nosarthur#216)

* reimplement gita clone nosarthur#202

The previous `gita clone config-file` corresponds to `gita clone -f config-file`

Now, by default
`gita clone <url>` translates to `git clone <url>` at the current
working directory

Also add `-C` option for changing current working directory before execution

fix rename repo issue: group file is not updated (nosarthur#207)

add color scheme reset nosarthur#189

clean up shell and super parsing (nosarthur#196)

add gita group -p option to modify group path nosarthur#187 (nosarthu…

…r#190)

add auto context (nosarthur#185)

add auto context

remove check=True in gita shell subprocss

Merge pull request nosarthur#170 from nosarthur/feature/auto-group

add auto-group

exclude newline on csv writer

fix test