Task 11/email reminders

[chandur626]

This pr contains the logic of sending emails to users if there are any reminders due in one day.

[codecov-commenter]

Codecov Report

Merging #52 (55ea954) into main (d6610e7) will decrease coverage by 2.76%.
The diff coverage is 35.29%.

@@            Coverage Diff             @@
##             main      #52      +/-   ##
==========================================
- Coverage   64.68%   61.92%   -2.77%     
==========================================
  Files          15       16       +1     
  Lines        1076     1145      +69     
==========================================
+ Hits          696      709      +13     
- Misses        380      436      +56     

Impacted Files	Coverage Δ
bot.py	0.00% <0.00%> (ø)
cogs/deadline.py	58.97% <20.00%> (-3.82%)	⬇️
test/test_bot.py	95.20% <66.66%> (-2.56%)	⬇️
cogs/email_address_spec.py	85.54% <0.00%> (-7.23%)	⬇️
Utility/email_utility.py	22.22% <0.00%> (ø)

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