Laravel Curl Error SSL certificate , Xero integration, Wamp

I have tried dowloading (http://ift.tt/1OeNMyn), setting location for certificate, I think i don't understand how certificates work, I mean which certificate is what, I am trying to connect xero in laravel, I am using drawmyattention xerophp, everything went smoot, but when i try to access

XeroPrivate::load('Accounting\\Invoice')->execute();

I get below error

[XeroPHP\Remote\Exception]
Curl error: SSL certificate problem: unable to get local issuer certificate

Even after downloading cacert.pem, adding it to ini file, then second thing i did was to use this function var_dump(openssl_get_cert_locations());

It suggested the location of cert.pem was

C:\usr\local\ssl\cert.pem

which didn't exited, I created that location manually with .pem file, but it still won't work.

I am using laravel 5+ Wamp server 3.0.6 it has curl 7.50

Any help would be appreciated.

via Chebli Mohamed