[add] added IF {condition} to FT.ADD API

[filipecosta90]

No description provided.

[codecov]

Codecov Report

Merging #33 into master will decrease coverage by 1.67%.
The diff coverage is 38.46%.

@@            Coverage Diff             @@
##           master      #33      +/-   ##
==========================================
- Coverage   63.39%   61.71%   -1.68%     
==========================================
  Files          12       12              
  Lines         896      896              
==========================================
- Hits          568      553      -15     
- Misses        270      279       +9     
- Partials       58       64       +6

Impacted Files	Coverage Δ
redisearch/client.go	67.25% <38.46%> (-0.4%)	⬇️
redisearch/query.go	73.83% <0%> (-12.41%)	⬇️

---

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 f0362cd...f05c46b. Read the comment docs.