Use bash for scripts instead of sh

[mportiz08]

Bug/issue #, if applicable:

Summary

This fixes a minor issue with some scripts in bin/ that use the shebang line #!/usr/bin/env sh.

When running on a system with an actual sh implementation, these scripts fail due to a syntax issue with the function keyword (apparently a bash specific thing). This is easy to miss on platforms where sh is just a link to bash, so using bash will ensure that the scripts work without changes on all platforms.

Testing

Steps:

1. Run npm run docs to exercise all these scripts and ensure they are still functional.

Checklist

Make sure you check off the following items. If they cannot be completed, provide a reason.

• Added tests
• Ran npm test, and it succeeded
• Updated documentation if necessary

[mportiz08]

@swift-ci test