Support Service Account Authentication method

[kevin-nessie]

Context

The current TAP implementation requires the usage of the api_secret to authenticate to mixpanel. However, this authentication method is deprecated. While mixpanel is still planning to keep supporting this authentication method, they strongly encourage developers to use the Service Account authentication method instead

Requirements

• Add support for Service Account authentication method in the tap-mixpanel
• Authentication with api_secret should still be supported by the tap-mixpanel
• Developers can only authenticate using one of the two methods, not both.

[uaibo]

I am getting this error too HTTP-error-code: 400, Error: request failed with error: invalid project id for cluster.
Unfortunately it looks like this project is dead. R.I.P. 🪦🙏🏻