Reduce of empty array with no initial value

[felixfbecker]

When I run graphql codegen, I only get the error

Reduce of empty array with no initial value

Adding an empty array as the initial value here fixes it: https://github.com/rricard/graphql-cli-codegen/blob/7a7bba9fc5a2a338f2f87243e82c90551e6132b0/src/codegen.ts#L47