Update Sms77api.py

[abao168899]

This pull request includes a significant change to the Sms77api.py file, specifically the addition of a new method for sending bulk SMS messages. The most important changes include the removal of two helper functions and the addition of the bulk_sms method.

New functionality:

• src/sms77api/Sms77api.py: Added the bulk_sms method to send multiple SMS messages in a single call. This method iterates over a list of messages, validates each message, and sends it using the existing sms method.

Code cleanup:

• src/sms77api/Sms77api.py: Removed the expect_json helper function, which was used to determine if a request should expect a JSON response.
• src/sms77api/Sms77api.py: Removed the local_params helper function, which was used to clean up local parameters.Send SMS in bulk

[abao168899]

This pull request introduces a significant new feature to the Sms77api class by adding a method for sending bulk SMS messages. Additionally, it removes two utility functions that are no longer needed. Below are the most important changes:

New Features:

• Added the bulk_sms method to the Sms77api class, which allows sending multiple SMS messages in a single call. This method takes a list of messages and an optional dictionary of parameters. Each message must contain 'to' and 'text' fields. (src/sms77api/Sms77api.py)

Code Cleanup:

• Removed the expect_json function, which was used to determine if the response should be in JSON format based on the endpoint and parameters. (src/sms77api/Sms77api.py)
• Removed the local_params function, which was used to filter out the 'self' parameter from the local variables dictionary. (src/sms77api/Sms77api.py)