Separate customer initializers of Mappables

Separate BaseMappable from ImmutableMappable.

Author: Rafael da Silva Ferreira

JSONStub.podspec

@@ -8,7 +8,7 @@
 
 Pod::Spec.new do |s|
   s.name             = 'JSONStub'
-  s.version          = '0.1.1'
+  s.version          = '0.1.2'
   s.summary          = 'Use JSONStub to easily load JSON files into your Mappable objects.'
 
 # This description is used to generate tags and improve search results.

JSONStub/Classes/BaseMappable.swift

@@ -6,7 +6,8 @@
 //  Copyright © 2016 Swift Yah. All rights reserved.
 //
 
-import ObjectMapper
+import struct Foundation.Data
+import protocol ObjectMapper.BaseMappable
 
 public extension BaseMappable {
     init?(fromFileName file: String) {

JSONStub/Classes/ImmutableMappable.swift

@@ -0,0 +1,21 @@
+//
+//  ImmutableMappable.swift
+//  Pods
+//
+//  Created by Rafael Ferreira on 3/30/17.
+//
+//
+
+import protocol ObjectMapper.ImmutableMappable
+
+public extension ImmutableMappable {
+    init?(fromFileName file: String) {
+        guard let json = file.fileDictionary() else { return nil }
+
+        do {
+            try self.init(JSON: json)
+        } catch {
+            return nil
+        }
+    }
+}