Squashed commit of the following:

commit f77ea0a
Author: Isaac Hernandez <isaacfi@gmail.com>
Date:   Tue Jul 9 21:12:29 2019 -0500

    Improvement solution for issue 311

    I've wrote a better solution replacing the references '$ref' with the recursive method __replace_ref

commit 3cb03f4
Author: Isaac Hernandez <isaacfi@gmail.com>
Date:   Mon Jun 24 08:52:34 2019 -0500

    Fix index

commit bdcfd33
Author: Isaac Hernandez <isaacfi@gmail.com>
Date:   Mon Jun 24 08:51:30 2019 -0500

    Validate if the referenced schema has divider

commit bf9c17e
Author: Isaac Hernandez <isaacfi@gmail.com>
Date:   Sun Jun 23 23:31:04 2019 -0500

    Remove the spaces in 361 line

commit bf262df
Author: Isaac Hernandez <isaacfi@gmail.com>
Date:   Sun Jun 23 23:16:13 2019 -0500

    Solution for issue #311

    Sorry for all changes, but it pretend to solve the issue #311 I loaded the main_def from file

flasgger/utils.py

@@ -6,6 +6,7 @@
 import inspect
 import os
 import re
+import sys
 import jsonschema
 import yaml
 from six import string_types, text_type
@@ -251,6 +252,40 @@ def wrapper(*args, **kwargs):
     return decorator
 
 
+def __replace_ref(schema: dict, relative_path: str):
+    """ TODO: add dev docs
+
+    :param schema:
+    :param relative_path:
+    :return:
+    """
+    absolute_path = os.path.dirname(sys.argv[0])
+    new_value = {}
+    for key, value in schema.items():
+        if isinstance(value, dict):
+            new_value[key] = __replace_ref(value, relative_path)
+        elif key == '$ref':
+            if len(value) > 0 and value[0] == '/':
+                file_ref_path = absolute_path + value
+            else:
+                file_ref_path = relative_path + '/' + value
+            relative_path = os.path.dirname(file_ref_path)
+            with open(file_ref_path) as file:
+                file_content = file.read()
+                comment_index = file_content.rfind('---')
+                if comment_index > 0:
+                    comment_index = comment_index + 3
+                else:
+                    comment_index = 0
+                content = yaml.safe_load((file_content[comment_index:]))
+                new_value = content
+                if isinstance(content, dict):
+                    new_value = __replace_ref(content, relative_path)
+        else:
+            new_value[key] = value
+    return new_value
+
+
 def validate(
         data=None, schema_id=None, filepath=None, root=None, definition=None,
         specs=None, validation_function=None, validation_error_handler=None):
@@ -359,6 +394,13 @@ def validate(
     if validation_function is None:
         validation_function = jsonschema.validate
 
+    absolute_path = os.path.dirname(sys.argv[0])
+    if filepath is None:
+        relative_path = absolute_path
+    else:
+        relative_path = os.path.dirname(filepath)
+    main_def = __replace_ref(main_def, relative_path)
+
     try:
         validation_function(data, main_def)
     except Exception as err:
@@ -808,6 +850,7 @@ class LazyString(StringLike):
     A lazy string *without* caching. The resulting string is regenerated for
     every request.
     """
+
     def __init__(self, func):
         """
         Creates a `LazyString` object using `func` as the delayed closure.
@@ -826,6 +869,7 @@ class CachedLazyString(LazyString):
     """
     A lazy string with caching.
     """
+
     def __init__(self, func):
         """
         Uses `__init__()` from the parent and initializes a cache.