Added jq to the macos setup script

The manual setup doc details that "If you are not on macOS or you don’t
have Homebrew, you need to install:", and then lists jq, but the
macos-setup.sh script doesn't install jq for you.

I also confirmed that jq is indeed necessary for the project via
bricking by not having it XD

scripts/macos-setup.sh

@@ -22,6 +22,9 @@ brew list pre-commit &>/dev/null || brew install pre-commit
 go get -u golang.org/x/tools/cmd/goimports
 go get -u golang.org/x/lint/golint
 
+echo "Installing jq..."
+brew list jq &>/dev/null || brew install jq
+
 echo "Installing pre-commit and specified hooks..."
 pre-commit install --install-hooks