Add class groups

[chaiwanlin]

closes #25

[codecov-commenter]

Codecov Report

Merging #92 (96c1677) into master (4196474) will decrease coverage by 1.41%.
The diff coverage is 45.12%.

@@             Coverage Diff              @@
##             master      #92      +/-   ##
============================================
- Coverage     62.27%   60.86%   -1.42%     
- Complexity      458      507      +49     
============================================
  Files            92      100       +8     
  Lines          1654     1855     +201     
  Branches        179      216      +37     
============================================
+ Hits           1030     1129      +99     
- Misses          582      661      +79     
- Partials         42       65      +23     

Impacted Files	Coverage Δ
src/main/java/seedu/edrecord/MainApp.java	0.00% <0.00%> (ø)
...java/seedu/edrecord/logic/commands/AddCommand.java	80.00% <0.00%> (-12.31%)	⬇️
...du/edrecord/logic/commands/ListModulesCommand.java	100.00% <ø> (ø)
...eedu/edrecord/logic/commands/MakeGroupCommand.java	0.00% <0.00%> (ø)
...va/seedu/edrecord/logic/parser/EdRecordParser.java	72.72% <0.00%> (-3.47%)	⬇️
...seedu/edrecord/logic/parser/EditCommandParser.java	86.66% <0.00%> (-6.20%)	⬇️
.../edrecord/logic/parser/MakeGroupCommandParser.java	0.00% <0.00%> (ø)
...edrecord/logic/parser/MakeModuleCommandParser.java	0.00% <0.00%> (ø)
src/main/java/seedu/edrecord/model/Model.java	100.00% <ø> (ø)
...odel/group/exceptions/DuplicateGroupException.java	0.00% <0.00%> (ø)
... and 25 more

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[FergusMok]

There's no checks to create a person to an existing class for now

Sample test case:

1. add n/Betsy Crowe p/1234567 e/betsycrowe@example.com m/CS2103 c/W-14-3 i/telegram @betyoass t/strong
   (W-14-3 is not held by the Module, but the Person has the class)
2. add n/Bob p/1234567 e/betsycrowe@example.com m/CS2103 c/W-3 i/telegram @betyoass t/strong
3. edit c/W-14-3

Error Message: Class with that code has yet to be created.

If we're rushing, we can shift this to another issue in 1.3

[chaiwanlin]

There's no checks to create a person to an existing class for now

Sample test case:

1. add n/Betsy Crowe p/1234567 e/betsycrowe@example.com m/CS2103 c/W-14-3 i/telegram @betyoass t/strong
   (W-14-3 is not held by the Module, but the Person has the class)
2. add n/Bob p/1234567 e/betsycrowe@example.com m/CS2103 c/W-3 i/telegram @betyoass t/strong
3. edit c/W-14-3

Error Message: Class with that code has yet to be created.

If we're rushing, we can shift this to another issue in 1.3

@FergusMok These test cases are all under Add..Test or Edit..Test already but I didn't have to change them because the TypicalModules and PersonBuilder takes class into consideration already. However I haven't added test cases for making mods and class I'll put those under v1.3 for now since I might not be able to rush them out yet

[marcusc55]

LGTM!

[FergusMok]

@chaiwanlin Sorry I meant non-existing class, I think it's a non-intended bug. I think test cases not super impt for now

[caipng]

Some minor nits.

[FergusMok]

LGTM

[caipng]

LGTM!