Shared libary without SO version

[glaubitz]

With the last release, aws-c-event-stream dropped its SO version.

However, this is not allowed according to spec as SO versions are mandatory for shared libraries.

Please see the full explanation that I gave for aws-c-common here: awslabs/aws-c-common#698

[yasminetalby]

Hello @glaubitz ,

I sincerely apologies for the delay of answer on this submission. We really appreciate your feedback.
This has been added to our backlog. I will post an update here once this issue is resolved.

Sincerely,

Yasmine

[jmklix]

This should be fixed with the linked PR