Node.js agent v1.18.5

Fixed a bug in environment variable based configuration.
Previously the agent would parse the NEW_RELIC_APDEX environment variable as a string rather than a float this could cause data to be sent to New Relic servers in an invalid format, preventing the data from being collected.
Fixed a bug with the error collector's handling of ignored status codes.
Previously the agent would not properly ignore status codes if the status code was set using a string rather than a number.
Fixed a bug in mysql instrumentation.
Previously the mysql instrumentation could cause errors when making mysql queries using an options object rather than a SQL string. The agent now handles arguments to the query method in a more robust way.