Added Binary Heap

[czgdp1807]

References to other Issues or PRs or Relevant literature

#42

Brief description of what is fixed or changed

Other comments

[czgdp1807]

ping @23umesh Apologies for closing your PR by mistake. Your commits are still there and your name will be added to authors file(only if you want). Let me know.

[codecov]

Codecov Report

Merging #46 into master will increase coverage by 0.107%.
The diff coverage is 99.038%.

@@              Coverage Diff              @@
##            master       #46       +/-   ##
=============================================
+ Coverage   97.895%   98.003%   +0.107%     
=============================================
  Files           15        17        +2     
  Lines          998      1102      +104     
=============================================
+ Hits           977      1080      +103     
- Misses          21        22        +1

Impacted Files	Coverage Δ
pydatastructs/trees/tests/test_binary_trees.py	100% <ø> (ø)	⬆️
pydatastructs/trees/tests/test_heaps.py	100% <100%> (ø)
pydatastructs/linear_data_structures/arrays.py	100% <100%> (ø)	⬆️
pydatastructs/trees/__init__.py	100% <100%> (ø)	⬆️
pydatastructs/trees/heaps.py	98.571% <98.571%> (ø)

[czgdp1807]

@23umesh As you given thumbs up to above comment, I am adding your name to the AUTHORS file. Please let me know your email-id in the comment below.

[czgdp1807]

For now I have added what was available on your Github profile. Make a PR if you want any changes. For now I will merge as soon as the tests pass. Thanks for the contribution.