storage: refactor MemStorage to support fault injection

[Fullstop000]

Signed-off-by: Fullstop000 [email protected]

[codecov]

Codecov Report

Merging #36 into master will increase coverage by 1.33%.
The diff coverage is 88.52%.

@@            Coverage Diff             @@
##           master      #36      +/-   ##
==========================================
+ Coverage   63.62%   64.95%   +1.33%     
==========================================
  Files          34       34              
  Lines        6031     6364     +333     
==========================================
+ Hits         3837     4134     +297     
- Misses       2194     2230      +36

Impacted Files	Coverage Δ
src/storage/mod.rs	48.27% <ø> (ø)	⬆️
src/storage/file.rs	96.15% <ø> (ø)	⬆️
src/lib.rs	100% <ø> (ø)	⬆️
src/options.rs	30.13% <100%> (+0.4%)	⬆️
src/sstable/table.rs	88.94% <100%> (ø)	⬆️
src/storage/mem.rs	87.11% <88.41%> (+2.67%)	⬆️

---

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 4654160...9912fea. Read the comment docs.