Segment Fixes for OSS and Dev Site Sources 🤯

[jpvajda]

Segment is confusing and things don't seem to be set up correctly, we are currently using the wrong write key for our Dev Site and OSS sites as each source as a unique write key. We also have 1 source for 2 sites point to a single URL in Segment which seems odd.

We need to have 2 distinct sources for opensource.newrelic.com and developer.newrelic.com as we currently have this setup:

NR OSS.com & Dev.com (Production)
NR OSS.com & Dev.com (Staging)

Which both point to opensource.newrelic.com.

NOTE: We don't have staging environments.

Acceptance Criteria

1. We need to actually have this setup:

developer.newrelic.com (Production) > developer.newrelic.com
opensource.newrelic.com (Production) > opensource.newrelic.com

3. @jpvajda needs the ability to view the write keys for both these properties. -This requires permissions
4. Once visible set the keys correctly on the OSS and Dev Site
5. @jpvajda would like to be able to use the event tester feature of segment to test this setup. - This requires permissions
6. When this is correctly setup, finish the testing for changes:

newrelic/opensource-website#737
#1199