fix(cli): return a non-zero exit code on failure (#11)

Previously, this script would silently fail when an error was encountered. This breaks builds. Now,
it will return an exit code of 1 when an error is encountered.

BREAKING CHANGE: This may lead to builds that previously succeeded breaking. This would mean that
there was previously an uncaught error in your setup. Well-configured, healthy builds should remain
unaffected.

Author: Steven Petryk

src/contentful-typescript-codegen.ts

@@ -67,6 +67,7 @@ async function runCodegen(outputFile: string) {
 
 runCodegen(cli.flags.output).catch(error => {
   console.error(error)
+  process.exit(1)
 })
 
 if (cli.flags.poll) {