Results 2 issues of pbalint

This change enables the github plugin to respect GitSCM's excluded user list (which is used when polling) for github webhooks: ![image](https://user-images.githubusercontent.com/4727754/68998493-3172d980-08b3-11ea-8088-c0e60863498d.png) This is a first attempt to solve the issue...

**Describe the bug** HttpExporterBuider.resolveHttpSenderProvider uses its own class loader for finding HttpSenderProvider-implementations: https://github.com/open-telemetry/opentelemetry-java/blob/77bb43942281ca2a5531ee6ef5fb6648505dc6a0/exporters/common/src/main/java/io/opentelemetry/exporter/internal/http/HttpExporterBuilder.java#L253 This does not work in an OSGi-environment, because simple class loaders like these are only able to...

Bug