Fixed handling for transaction

[jinSasaki]

I fixed a bug that fallbackHandler does not handle with transactionState.

[codecov]

Codecov Report

Merging #31 into master will decrease coverage by 0.2%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master      #31      +/-   ##
==========================================
- Coverage   97.03%   96.83%   -0.21%     
==========================================
  Files           6        6              
  Lines         236      221      -15     
==========================================
- Hits          229      214      -15     
  Misses          7        7

Impacted Files	Coverage Δ
Sources/InAppPurchase.swift	100% <100%> (ø)	⬆️
Sources/Internal/Internal+InAppPurchase.swift	100% <100%> (ø)	⬆️

---

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 0a72de5...078a3bd. Read the comment docs.