Added separator spaces to accept-encoding and accept-language header fields.

Source/Manager.swift

@@ -45,13 +45,13 @@ public class Manager {
     */
     public static let defaultHTTPHeaders: [String: String] = {
         // Accept-Encoding HTTP Header; see https://tools.ietf.org/html/rfc7230#section-4.2.3
-        let acceptEncoding: String = "gzip;q=1.0,compress;q=0.5"
+        let acceptEncoding: String = "gzip;q=1.0, compress;q=0.5"
 
         // Accept-Language HTTP Header; see https://tools.ietf.org/html/rfc7231#section-5.3.5
         let acceptLanguage = NSLocale.preferredLanguages().prefix(6).enumerate().map { index, languageCode in
             let quality = 1.0 - (Double(index) * 0.1)
             return "\(languageCode);q=\(quality)"
-        }.joinWithSeparator(",")
+        }.joinWithSeparator(", ")
 
         // User-Agent Header; see https://tools.ietf.org/html/rfc7231#section-5.5.3
         let userAgent: String = {