0.0.5 release to central

An incompatible change was made in the encoding of numbers in the trace and span headers. Prior to
0.0.5, the numbers were encoded in hexadecimal. From 0.0.5 onwards the encoding is in decimal.

Additionally, prior to version 0.0.5, the parsing of header did not handle invalid numbers. To upgrade without downtime, rebuild and deploy the more dependent services first.