Add requirements to Lint phase of Actions workflow

[sampreet-arthi]

Causing a problem with existing PRs. We should ideally move to using later versions of isort and black but we can do that later.

[sampreet-arthi]

Accidentally pushed code from the Off Policy Trainer Refactoring

[codecov[bot]]

Codecov Report

Merging #289 into master will decrease coverage by 0.02%. The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #289      +/-   ##
==========================================
- Coverage   89.65%   89.63%   -0.03%     
==========================================
  Files          87       87              
  Lines        3752     3752              
==========================================
- Hits         3364     3363       -1     
- Misses        388      389       +1     

Impacted Files	Coverage Δ
genrl/agents/classical/sarsa/sarsa.py	96.15% <0.00%> (-3.85%)	:arrow_down:

[sampreet-arthi]

Merge this @Sharad24 ?