Optional email service proper handling

[that-one-arab]

Description:

As per the docs, email service should be optionally provided.

But the code requires it.

If we do not provide it, an exception is raised due to missing environment variables

If we provide it with incorrect values (such as the values in the example .env we get error TypeError: Converting circular structure to JSON when we try to login using google oauth.

This error, when traced, is due to the below request error sent to api.convertkit.com

data: { error: 'Authorization Failed', message: 'API Key not valid' }

This is how the request URL looks like https://api.convertkit.com/v3/tags/YOUR_LIST_ID/subscribe?api_secret=UNIQUE_SECRET_FROM_YOUR_CONVERTKIT_ACCOUNT&[email protected]&first_name=my-name so an error is expected to happen here.

This PR handles the aforementioned case

Adding Feature(s):

• Make email service optional.

Fixing Issue(s):

• Error during oauth sign in due to incorrect email environment variables

Changes