Add exported go function cycletls.NewTransport()

[deoxykev]

This PR addresses #151

The idea is to be able to export the http.Client Transport, so we are able to use CycleTLS in our own http.Clients.

There are two new Exported functions:

• NewTransport()
• NewTransportWithProxy

Example Usage:

import (
	"github.com/Danny-Dasilva/CycleTLS/cycletls"
	http "github.com/Danny-Dasilva/fhttp" // note this is a drop-in replacement for net/http
)

func main() {
	ja3 := "771,52393-52392-52244-52243-49195-49199-49196-49200-49171-49172-156-157-47-53-10,65281-0-23-35-13-5-18-16-30032-11-10,29-23-24,0"
	ua := "Chrome Version 57.0.2987.110 (64-bit) Linux"

 	 cycleClient := &http.Client{
 		Transport:     cycletls.NewTransport(ja3, ua),
 	 }

	resp, err := cycleClient.Get("https://tls.peet.ws/")
	...
}

The caveat here is having to use the drop-in replacement for net/http: github.com/Danny-Dasilva/fhttp everywhere net/http is used. But in my testing, it seems to work well.

[Danny-Dasilva]

Nice, I'll get this merged in

[deoxykev]

Thanks for all your work on this library, I really appreciate it.