Added singleton config and changed module structure

neuroapi/_neuroapi.py

@@ -0,0 +1,11 @@
+from ._methods.admin import Admin
+from ._methods.image import Image
+from ._methods.post import Post
+from ._methods.user import User
+
+
+class neuroapi:
+    post = Post()
+    admin = Admin()
+    user = User()
+    image = Image()