getFormattedPhoneNumber returns invalid phone string

[mgray88]

Describe the bug getFormattedPhoneNumber returns an invalid phone string

To Reproduce Steps to reproduce the behavior:

1. Call set(phoneNumber:) with a valid phone string
2. Use the keyboard to delete all text from the text field
3. getFormattedPhoneNumber(format: .E164) returns "+(null)(null)"

Expected behavior Expect getFormattedPhoneNumber to return null if the phone number is invalid

Smartphone (please complete the following information):

• Device: iPhone 5s
• OS: iOS 10.3.4

FlagPhoneNumber (please complete the following information):

• Version 0.7.6

[mgray88]

Actually, set(phoneNumber:) isn't even required, getFormattedPhoneNumber returns the invalid string regardless