Longest Increasing Subsequence added

[sHiVaNgI821]

Added the longest_increasing_subsequence method that returns the longest strictly increasing subsequence that can be obtained from the given array. The lower_bound function used in the implementation has been taken from #351

References to other Issues or PRs or Relevant literature

Brief description of what is fixed or changed

Other comments

[codecov]

Codecov Report

Merging #363 (a9f6445) into master (e1134b1) will increase coverage by 0.021%.
The diff coverage is 100.000%.

@@              Coverage Diff              @@
##            master      #363       +/-   ##
=============================================
+ Coverage   98.561%   98.583%   +0.021%     
=============================================
  Files           25        25               
  Lines         3267      3317       +50     
=============================================
+ Hits          3220      3270       +50     
  Misses          47        47               

Impacted Files	Coverage Δ
pydatastructs/linear_data_structures/__init__.py	100.000% <ø> (ø)
pydatastructs/linear_data_structures/algorithms.py	99.676% <100.000%> (+0.062%)	⬆️