As a user I want to add a new account

1. Click on the Alby Extension
2. Pop up window appears
3. Go to the account list on the left
4. Scroll down to "add a new account"
5. Click on "add a new account"
6. "Add a new lightning account" window appears
7. Click on Alby Wallet icon
8. "Your Alby Lightning Wallet" window appears
9. Input email address
10. Input password
11. Choose your Lightning Address (optional)
12. Click on "Continue"
13. "Success" window appears