FieldType add boolean

[RobertoAntonello]

Describe the bug
in enum FieldType need to add "boolean"

To Reproduce
Steps to reproduce the behavior:

1. var df = await client.DealField.GetAll();
2. Error converting value "boolean" to type 'Pipedrive.FieldType'
   System.ArgumentException: Requested value 'boolean' was not found.

[konius]

We're also experiencing the issue. Are there any plans to patch this?