Ensure default expiration parameter is set for presigned URLs

[bdalpe]

Resolves #1312

Additionally, remove unnecessary isFunction checks as that is now handled by the callbackify wrapper.

Added module in unit test library for better coverage.

[prakashsvmx]

@bdalpe , Thank you, could you please resolve the lint/format issues ?

[bdalpe]

@prakashsvmx update pushed to fix the formatting issue in the test

[septatrix]

This is quite a significant breakage. Could we please get a bugfix release ASAP?