Add e2e test for repro, fix formula.py newline

[gtalarico]

• Add e2e/write.py for quick tests
• Fix newline formatting error merged accidently

[codecov-commenter]

Codecov Report

Merging #155 (88f7fc8) into main (be1b5c4) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main     #155   +/-   ##
=======================================
  Coverage   87.01%   87.01%           
=======================================
  Files          13       13           
  Lines         593      593           
=======================================
  Hits          516      516           
  Misses         77       77           

Impacted Files	Coverage Δ
pyairtable/formulas.py	84.44% <ø> (ø)

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