New Homebrew Warnings

[ecbrodie]

I noticed on a brew upgrade today some new warnings pertaining to this package that I have not seen before:

```Warning: Calling cellar in a bottle block is deprecated! Use `brew style --fix` on the formula to update the style or use `sha256` with a `cellar:` argument instead.
Please report this issue to the shopify/shopify tap (not Homebrew/brew or Homebrew/core), or even better, submit a PR to fix it:
/usr/local/Homebrew/Library/Taps/shopify/homebrew-shopify/secret-sender.rb:13

Warning: Calling sha256 "digest" => :tag in a bottle block is deprecated! Use brew style --fix on the formula to update the style or use sha256 tag: "digest" instead.
Please report this issue to the shopify/shopify tap (not Homebrew/brew or Homebrew/core), or even better, submit a PR to fix it:
/usr/local/Homebrew/Library/Taps/shopify/homebrew-shopify/secret-sender.rb:15

Warning: Calling cellar in a bottle block is deprecated! Use brew style --fix on the formula to update the style or use sha256 with a cellar: argument instead.
Please report this issue to the shopify/shopify tap (not Homebrew/brew or Homebrew/core), or even better, submit a PR to fix it:
/usr/local/Homebrew/Library/Taps/shopify/homebrew-shopify/secret-sender.rb:19

Warning: Calling sha256 "digest" => :tag in a bottle block is deprecated! Use brew style --fix on the formula to update the style or use sha256 tag: "digest" instead.
Please report this issue to the shopify/shopify tap (not Homebrew/brew or Homebrew/core), or even better, submit a PR to fix it:
/usr/local/Homebrew/Library/Taps/shopify/homebrew-shopify/secret-sender.rb:22

It looks like there is some TLC needed for this package to keep up with latest Homebrew changes and deprecations.