Instead of custom attributes, leverage the status description as
described in Semantic Conventions. This approach is taken from current
`opentelemetry_ecto` implementation.
Small non-related change is a fix the license description in `mix.exs`.
Initial approach follows Ecto instrumentation, recording spans for all
Redix `[:redix, :pipeline, :stop]` events.
The command sanitization is inspired-by and adapted from [Java
instrumentation][1], from where I've also copied the actual commands and
what configuration should they follow.
Network attributes are tracked via a "sidecar" process, which keeps
track of connection attributes also via `telemetry`. This extra bit of
bookkeeping is needed as command events doesn't include that piece of
information, unfortunately.
[1]: b2bc41453b/instrumentation-api/src/main/java/io/opentelemetry/instrumentation/api/db/RedisCommandSanitizer.java
Andrew Rosa