Test Using 'Raises' are now asserted!

[TarunTomar122]

Fixes #52 by asserting the raises.

Brief description of what is fixed or changed

changed all the raises(.....) to
assert raises(.....)

Other comments

[czgdp1807]

Thanks for the PR. The tests will fail for now. If @rohansingh9001 doesn't complete #51 by tomorrow then I will make a follow up PR.

[codecov]

Codecov Report

Merging #54 into master will increase coverage by 0.172%.
The diff coverage is 100%.

@@              Coverage Diff              @@
##            master       #54       +/-   ##
=============================================
+ Coverage   98.005%   98.177%   +0.172%     
=============================================
  Files           17        19        +2     
  Lines         1103      1262      +159     
=============================================
+ Hits          1081      1239      +158     
- Misses          22        23        +1

Impacted Files	Coverage Δ
...tructs/linear_data_structures/tests/test_arrays.py	100% <100%> (ø)	⬆️
pydatastructs/trees/tests/test_binary_trees.py	100% <100%> (ø)	⬆️
.../miscellaneous_data_structures/tests/test_stack.py	100% <100%> (ø)	⬆️
...tructs/trees/tests/test_space_partitioning_tree.py	100% <100%> (ø)	⬆️
pydatastructs/utils/misc_util.py	95.833% <0%> (-4.167%)	⬇️
pydatastructs/linear_data_structures/__init__.py	100% <0%> (ø)	⬆️
pydatastructs/utils/__init__.py	100% <0%> (ø)	⬆️
pydatastructs/utils/raises_util.py	100% <0%> (ø)	⬆️
.../linear_data_structures/tests/test_linked_lists.py	100% <0%> (ø)
...datastructs/linear_data_structures/linked_lists.py	100% <0%> (ø)