Switch to go-swagger for client lib and checks for IRON_TOKEN (#406)

* wip - for review, using go-swagger client and checking for IRON_TOKEN and passing as auth header.

* wip - auth header

* add golang builder

* finish client builder

* change gh username

* fix git command

* update readme and small fixes

* some improvements

* using go-swagger

* fn new client

* revert swagger

* make fn routes and apps work with new client (go-swagger)

* some fixes in fn apps

* update functions_go

fn/api.go

@@ -0,0 +1,37 @@
+package main
+
+import (
+	"os"
+
+	httptransport "github.com/go-openapi/runtime/client"
+	"github.com/go-openapi/strfmt"
+	fnclient "github.com/iron-io/functions_go/client"
+	"log"
+	"net/url"
+)
+
+func host() string {
+	apiURL := os.Getenv("API_URL")
+	if apiURL == "" {
+		apiURL = "http://localhost:8080"
+	}
+
+	u, err := url.Parse(apiURL)
+	if err != nil {
+		log.Fatalln("Couldn't parse API URL:", err)
+	}
+
+	return u.Host
+}
+
+func apiClient() *fnclient.Functions {
+	transport := httptransport.New(host(), "/v1", []string{"http"})
+	if os.Getenv("IRON_TOKEN") != "" {
+		transport.DefaultAuthentication = httptransport.BearerToken(os.Getenv("IRON_TOKEN"))
+	}
+
+	// create the API client, with the transport
+	client := fnclient.New(transport, strfmt.Default)
+
+	return client
+}