don't specify `environ` as argument of the `request_started` signal (#233)
don't specify `environ` as argument of the `request_started` signal (#233)

Django Channels doesn't provide environ when calling signal handlers.
As we don't need it anyway, we can simply accept any arguments.

Fixes #232
Closes #233

beniwohli/apm-agent-python,beniwohli/apm-agent-python,beniwohli/apm-agent-python,beniwohli/apm-agent-python