add row_id to cassandra for long polling

[kcajmagic]

No description provided.

[codecov-io]

Codecov Report

Merging #25 into master will increase coverage by 0.72%.
The diff coverage is 72.5%.

@@            Coverage Diff             @@
##           master      #25      +/-   ##
==========================================
+ Coverage    51.9%   52.62%   +0.72%     
==========================================
  Files          15       15              
  Lines         921      952      +31     
==========================================
+ Hits          478      501      +23     
- Misses        441      448       +7     
- Partials        2        3       +1

Impacted Files	Coverage Δ
cassandra/executer.go	0% <0%> (ø)	⬆️
postgresql/db.go	39.06% <50%> (-0.42%)	⬇️
cassandra/db.go	59.13% <90%> (+8.56%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 601199a...e745819. Read the comment docs.

[kristinapathak]

Other than the small changes and what we talked about, it looks great!

[kristinapathak]

Suggested change

	// GetRecords returns a list of records for a given device after a hash
	// GetRecords returns a list of records for a given device after a hash.