proxy flag added

[gozeloglu]

• main.go simplified
• network related lines moved to src/client.go
• proxy is set to client.

I did not create a new file named as proxy.go, because it seems not really necessary for now. There is no special task related to proxy. But, we can discuss about creating a new file.

Update after 7be7d0c commit

I added proxy.go file to handle proxy related tasks.

Usage

gURL is open source CLI tool written in Go.

Usage:
  gURL [options...] <url> [flags]
  gURL [command]

Available Commands:
  GET         Fetches data from given url
  help        Help about any command

Flags:
  -h, --help           help for gURL
  -x, --proxy string   [protocol://]host[:port] Use this proxy

Use "gURL [command] --help" for more information about a command.

--proxy or -x flags takes string input.

Example Usage

$ gurl --proxy proxy://myproxy:8080 www.mysite.com
$ gurl -x proxy://myproxy:8080 www.mysite.com

[gozeloglu]

Before merging it, I need to add something.