iOS logs like "adb logcat" for simulator and real device

#### Setting up new features
```sh
./reset.sh --ios --verbose
```

######  Supported log types : logcat, idevice, isimulator
```python
self.driver.log_types
```

######  iOS logs for simulator 

```python
self.driver.get_log("isimulator")
```

######  iOS logs for real device

```python
self.driver.get_log("idevice")
```
<br/>
#### Fixed an issue in grunt configuration
maxBuffer increased to 2000*1024 due to problems with "maxBuffer exceeded" for selendroid building