Add unit tests for allocate, deallocate, reallocate commands and JsonAdaptedRoom

[jetnew]

What this does

This PR adds testing support for allocate, deallocate, reallocate commands and JsonAdaptedRoom. It adds unit tests for AllocateCommand, DeallocateCommand, ReallocateCommand and JsonAdaptedRoom.

Part of #13, #14 and #18.

How to test

N/A

Notes

1. Support for integration tests for AllocateCommand, DeallocateCommand and ReallocateCommand have to be added.

[codecov-io]

Codecov Report

Merging #106 into master will increase coverage by 6.25%.
The diff coverage is 100.00%.

@@             Coverage Diff              @@
##             master     #106      +/-   ##
============================================
+ Coverage     63.04%   69.30%   +6.25%     
- Complexity      732      788      +56     
============================================
  Files           127      127              
  Lines          2690     2691       +1     
  Branches        331      331              
============================================
+ Hits           1696     1865     +169     
+ Misses          903      716     -187     
- Partials         91      110      +19     

Impacted Files	Coverage Δ	Complexity Δ
...in/java/seedu/resireg/storage/JsonAdaptedRoom.java	97.43% <100.00%> (+97.43%)	9.00 <0.00> (+9.00)
src/main/java/seedu/resireg/model/room/Room.java	70.27% <0.00%> (+2.70%)	18.00% <0.00%> (+1.00%)
...va/seedu/resireg/model/room/roomtype/RoomType.java	90.90% <0.00%> (+9.09%)	8.00% <0.00%> (+1.00%)
src/main/java/seedu/resireg/model/room/Floor.java	90.00% <0.00%> (+10.00%)	7.00% <0.00%> (+1.00%)
...main/java/seedu/resireg/model/room/RoomNumber.java	90.00% <0.00%> (+10.00%)	7.00% <0.00%> (+1.00%)
...ava/seedu/resireg/model/allocation/Allocation.java	43.33% <0.00%> (+10.00%)	8.00% <0.00%> (+2.00%)
...resireg/model/allocation/UniqueAllocationList.java	55.76% <0.00%> (+11.53%)	16.00% <0.00%> (+2.00%)
...rc/main/java/seedu/resireg/model/ModelManager.java	86.89% <0.00%> (+12.41%)	47.00% <0.00%> (+5.00%)
src/main/java/seedu/resireg/model/ResiReg.java	90.27% <0.00%> (+13.88%)	28.00% <0.00%> (+4.00%)
.../seedu/resireg/logic/commands/AllocateCommand.java	80.55% <0.00%> (+75.00%)	9.00% <0.00%> (+8.00%)
... and 4 more

---

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 8f58e2d...3bcbcc8. Read the comment docs.

[chloelee767]

LGTM!

[Lysire]

LGTM!