configures API endpoints to cache results, updates dependencies versions, and updates travis for ubuntu focal

[azneto]

This pull request addresses issue #...

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I have read the CONTRIBUTING.rst file and understand that
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checks pass with these changes.

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[sonarqubecloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

No Coverage information
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[codecov-commenter]

Codecov Report

Merging #332 (fd1c159) into master (ffddba8) will decrease coverage by 1.14%.
The diff coverage is 1.19%.

@@            Coverage Diff             @@
##           master     #332      +/-   ##
==========================================
- Coverage   68.71%   67.57%   -1.15%     
==========================================
  Files          30       30              
  Lines        4060     4129      +69     
  Branches      235      717     +482     
==========================================
  Hits         2790     2790              
- Misses       1211     1280      +69     
  Partials       59       59              

Impacted Files	Coverage Δ
machado/api/urls.py	0.00% <0.00%> (ø)
machado/api/views.py	0.00% <0.00%> (ø)
machado/urls.py	76.92% <100.00%> (ø)

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