Add functional test for SB unsubscribe/resubscribe with incrementing count

**Is your feature request related to a problem? Please describe.**
#419 Updated sequence counter behavior.  Need to add a functional test to cover it.

**Describe the solution you'd like**
Add a functional test.

**Describe alternatives you've considered**
N/A

**Additional context**
N/A

**Requester Info**
Jacob Hageman - NASA/GSFC