Set default branch to gh-pages (fix #1151)

[nickmccurdy]

Description

Set default branch to gh-pages (fix #1151)

Testing Instructions

Running typecheck and test scripts, and updating integration tests to rely on the default branch

[codecov-commenter]

Codecov Report

Merging #1155 (d8c5cba) into dev (fea0c86) will increase coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##              dev    #1155      +/-   ##
==========================================
+ Coverage   98.19%   98.20%   +0.01%     
==========================================
  Files           7        7              
  Lines         277      279       +2     
  Branches       74       76       +2     
==========================================
+ Hits          272      274       +2     
  Misses          5        5              

Impacted Files	Coverage Δ
src/lib.ts	100.00% <100.00%> (ø)
src/util.ts	98.18% <100.00%> (ø)

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