Fix bugs

[derekjxtan]

Fixed:

1. nric error message closes #225, closes #195
2. help command not working closes #201

[codecov[bot]]

Codecov Report

Merging #242 (29f1e2e) into master (8fd3fc2) will decrease coverage by 0.03%. The diff coverage is 0.00%.

@@             Coverage Diff              @@
##             master     #242      +/-   ##
============================================
- Coverage     81.04%   81.01%   -0.03%     
  Complexity      938      938              
============================================
  Files           137      137              
  Lines          2823     2824       +1     
  Branches        275      275              
============================================
  Hits           2288     2288              
- Misses          502      503       +1     
  Partials         33       33              

Files	Coverage Δ
src/main/java/seedu/address/model/person/Nric.java	93.75% <ø> (ø)
.../seedu/address/logic/parser/MediConnectParser.java	92.50% <0.00%> (-2.38%)	:arrow_down:

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