A terminal-aware pretty reporter

A terminal-aware pretty reporter that simply displays test results using a status bar

```
Total: [✔✔✔✔✔✔✔✔✔✔] 131/131
Passed: 131  Failed: 0  Skipped: 0
````

```
IE 9:       Unit [✔︎~✔︎×✔︎✔︎✔︎✔︎✔︎✔︎] 100/100, 2 fail, 1 skip
Cov 100/89% Func [✔︎~✔︎×✔︎✔︎✔︎✔︎✔︎✔︎] 100/100, 2 fail, 1 skip
IE 10:      Unit [✔︎~✔︎×✔︎✔︎/   ]  65/100, 2 fail, 1 skip
            Func [          ]   0/100
Fx 24.0.1:  Unit [/         ]   2/100
            Func [          ]   0/100
Chr 32:     Starting

Saf 7:      Pending

Android 19: Pending
```
Nit: https://github.com/theintern/intern/pull/283/files?diff=unified#r18708003