Allow use of custom http.Client.

One purpose for this is to allow specifying a proxy.

basic_client_test.go

@@ -0,0 +1,31 @@
+package ofxgo
+
+import (
+	"errors"
+	"net"
+	"net/http"
+	"strings"
+	"testing"
+)
+
+func TestBasicClient_HTTPClient(t *testing.T) {
+	c := &BasicClient{
+		HTTPClient: &http.Client{
+			Transport: &http.Transport{
+				Dial: func(network, addr string) (net.Conn, error) {
+					return nil, errors.New("bad test client")
+				},
+			},
+		},
+	}
+	_, err := c.Request(&Request{
+		URL: "https://test",
+		Signon: SignonRequest{
+			UserID:   "test",
+			UserPass: "test",
+		},
+	})
+	if err == nil || !strings.Contains(err.Error(), "bad test client") {
+		t.Fatalf("expected error containing 'bad test client', got: %v", err)
+	}
+}