Update URLs from HTTP to HTTPS in release instructions

[pjfanning]

seems better to encourage HTTPS

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 87.11%. Comparing base (f554608) to head (afc2150).
⚠️ Report is 288 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff              @@
##             master     #317      +/-   ##
============================================
+ Coverage     86.54%   87.11%   +0.56%     
+ Complexity     9787       89    -9698     
============================================
  Files           532      499      -33     
  Lines         35516    33459    -2057     
  Branches       6194     5833     -361     
============================================
- Hits          30738    29148    -1590     
+ Misses         3518     3189     -329     
+ Partials       1260     1122     -138     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.