Describe the bug
When working with the DateRangePicker, if we want to change only the end date of the component, this is possible through the "end" input and not through a single calendar selection.

To Reproduce

1. Open this StackBlitz example
2. Select the END input. The Calendar will open
3. Click on a date in the Calendar
4. The selected date is being set to the "Start" value of the component.

Expected behavior
If the "End" input is focused, when we click on a date in the component's Calendar, only the "End" value should be changed.

Describe the bug
If we try to manually enter a value in the 'Start' input of the DateRangePicker, the entered value is applied to its 'End' input.

To Reproduce

1. Open this StackBlitz example
2. In the "Start" input select the field that holds the '5' digit. Now we can edit the day of the month for the Start date
3. Enter 8 with the keyboard

Expected behavior
The value of the "Start" input should be updated to 9/8/2018. Instead, the value of the "End" input is being changed to "9/8/2018" and the "Start" day continues to be "9/5/2018".

Screenshots