Add seedData functionality

[kokerinks]

Closes #9

[codecov]

Codecov Report

Attention: Patch coverage is 92.30769% with 1 lines in your changes are missing coverage. Please review.

Project coverage is 75.86%. Comparing base (1d27b90) to head (5baf283).
Report is 17 commits behind head on master.

Files	Patch %	Lines
.../seedu/address/logic/parser/AddressBookParser.java	0.00%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##             master      #40      +/-   ##
============================================
+ Coverage     75.26%   75.86%   +0.60%     
- Complexity      419      426       +7     
============================================
  Files            71       72       +1     
  Lines          1338     1351      +13     
  Branches        126      129       +3     
============================================
+ Hits           1007     1025      +18     
+ Misses          301      295       -6     
- Partials         30       31       +1     

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[billyhoce]

Implementation looks good! But test cases might not be as complete, after fixing that, it should be all good!

[billyhoce]

Also, you might want to consider using main/java/seedu.address/model/util/SampleDataUtil

[billyhoce]

LGTM!

[kinjalagarwal1810]

Looks good!