Amazon Certification Issue

I'm trying to get Cloud Storage working with Amazon's s3 solution, but the service is unable to find a certificate. However, I do have a certificate set up. I'm using one of the publicly available certs found here: https://raw.githubusercontent.com/bagder/ca-bundle/master/ca-bundle.crt

Now, if I'm in Tinker, I can do this:

>>> Cloud::put('test.txt', 'Hello World');
=> true
>>> Cloud::get('test.txt');
=> "Hello World"

And this uses the s3 driver just fine. I even inspected the server online, and it had the test.txt file. However, whenever my application attempts to do the same thing, I get this error:

Error executing "ListObjects" on "https://s3.amazonaws.com/haloco.dev.amxbase?prefix=uploads%2F4%2F2%2Ff%2F42ffe12a-2afb-42e9-83a1-ebc0226560c4.txt%2F&max-keys=1&encoding-type=url"; AWS HTTP error: cURL error 60: SSL certificate problem: unable to get local issuer certificate (see http://curl.haxx.se/libcurl/c/libcurl-errors.html)

And here's what's worse: I've had other people download my project, and do the exact same setup that I did, and it works just fine for them. I have no idea why this is failing on only my machine.