New reporter "info"

We switched from Google Test to Bandit and none of the reporters was "nice" enough. Coming from reporter "spec", a new reporter "info" is more colorful, less indented, and shows some begin/end information for describes which is useful to follow large lists of "it"s. Also skipped tests are not shown.
The output is also good to use for test code that produces output. Here is an uncolored example:

```
begin foo
  [ PASS ] example test A
  [ PASS ] example test B
  [ TEST ] example test C
output of  example test C
  [ PASS ] example test C
  [ PASS ] example test D
  [ FAIL ] example test E
end foo
```

PS: I also want to change the summary at the end. But I think a pull request now is also fine.