Fixed _left_rotate and _right_rotate

[Aimaanhasan]

References to other Issues or PRs or Relevant literature

Fixes #234

Brief description of what is fixed or changed

Removed assumption rotates were making for parent of j.

Other comments

See Issue #234

[codecov]

Codecov Report

Merging #238 into master will increase coverage by 0.015%.
The diff coverage is 100.000%.

@@              Coverage Diff              @@
##            master      #238       +/-   ##
=============================================
+ Coverage   98.562%   98.578%   +0.015%     
=============================================
  Files           24        24               
  Lines         2087      2110       +23     
=============================================
+ Hits          2057      2080       +23     
  Misses          30        30               

Impacted Files	Coverage Δ
pydatastructs/trees/binary_trees.py	96.975% <100.000%> (+0.024%)	⬆️
pydatastructs/linear_data_structures/__init__.py	100.000% <0.000%> (ø)
pydatastructs/linear_data_structures/algorithms.py	100.000% <0.000%> (ø)
pydatastructs/trees/heaps.py	97.837% <0.000%> (+0.035%)	⬆️

[czgdp1807]

Please add a regression test(your example in the issue) in test_binary_tree.py.

def test_issue_234():
    """
    link to issue
    """
    # your example    

[czgdp1807]

Any updates?

[Aimaanhasan]

Added the test @czgdp1807.

[czgdp1807]

Thank you for the efforts. Merging.