Due to we use pgbouncer, we could share the same instance of the metrics
gatherer singleton in multiples requests. Added support to have
multiple instances identified by transaction id
- It's not mandatory to have the log_path defined for all the services
- Now we add metrics to a MetricsGatherer using the add method in order
to gather data from all the function scope, not just in one defined
point
- There is a `metrics` context manager to wrap the function block. This
context manager get the execution time for the block among other
things
- Moved the logic the retrieve the redis connection params to
RedisDBConfig class
- Moved the logic that retrieve the services configuration to
ServicesDBConfig