[Migrate CI] Added workflow for GitHub actions CI. Deleted travis.yml.

[anvithks]

What type of PR is this? /kind enhancement

What this PR does / why we need it: This PR adds the Which issue(s) this PR fixes:

Fixes #1314

Test Report Added?: /kind TESTED

Test Report: The workflow run status can be seen in the Actions Tab.

Special notes for your reviewer:

[codecov[bot]]

Codecov Report

Merging #1315 (43a02e2) into master (7eb8236) will decrease coverage by 2.55%. The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #1315      +/-   ##
==========================================
- Coverage   41.48%   38.93%   -2.56%     
==========================================
  Files          53       53              
  Lines        7752     6966     -786     
==========================================
- Hits         3216     2712     -504     
+ Misses       4021     3739     -282     
  Partials      515      515              

Impacted Files	Coverage Δ
client/volume.go	62.31% <0.00%> (-8.40%)	:arrow_down:
client/fileshare.go	65.95% <0.00%> (-7.22%)	:arrow_down:
client/dock.go	42.85% <0.00%> (-7.15%)	:arrow_down:
client/pool.go	42.85% <0.00%> (-7.15%)	:arrow_down:
client/host.go	61.11% <0.00%> (-6.98%)	:arrow_down:
client/version.go	46.15% <0.00%> (-6.79%)	:arrow_down:
client/profile.go	55.55% <0.00%> (-6.42%)	:arrow_down:
pkg/api/policy/policy.go	25.88% <0.00%> (-5.19%)	:arrow_down:
pkg/api/controllers/version.go	65.21% <0.00%> (-4.02%)	:arrow_down:
pkg/api/controllers/base.go	76.74% <0.00%> (-3.26%)	:arrow_down:
... and 43 more

[skdwriting]

CI migration in progerss to github actions, local ci ok. hence merging.