Update required python version in readme

[danwom]

Summary of Changes

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Tests

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Documentation

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CheckList

Make sure you have checked all steps below to ensure a timely review.

• PR title addresses the issue accurately and concisely. Example: "Updates the version of Flask to v1.0.2"
  • In case you are adding a dependency, check if the license complies with the ASF 3rd Party License Policy.
• PR includes a summary of changes, including screenshots of any UI changes.
• PR adds unit tests, updates existing unit tests, OR documents why no test additions or modifications are needed.
• In case of new functionality, my PR adds documentation that describes how to use it.
  • All the public python functions and the classes in the PR contain docstrings that explain what it does
• PR passes all tests documented in the developer guide

[codecov-io]

Codecov Report

Merging #388 into master will decrease coverage by 2.2%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #388      +/-   ##
==========================================
- Coverage   75.32%   73.12%   -2.21%     
==========================================
  Files         168       28     -140     
  Lines        4199     1250    -2949     
  Branches      522      111     -411     
==========================================
- Hits         3163      914    -2249     
+ Misses       1000      307     -693     
+ Partials       36       29       -7

Impacted Files	Coverage Δ
...ication/static/js/components/common/Tabs/index.tsx
...ndsen_application/static/js/ducks/search/api/v0.ts
...ion/static/js/components/PreferencesPage/index.tsx
...tic/js/components/common/EditableText/constants.ts
...ication/static/js/components/common/Flag/index.tsx
...ts/common/ResourceListItem/TableListItem/index.tsx
...sen_application/static/js/ducks/allTags/reducer.ts
...tatic/js/components/common/ScrollTracker/index.tsx
...pplication/static/js/ducks/popularTables/api/v0.ts
.../js/components/TableDetail/ExploreButton/index.tsx
... and 130 more

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