Correct example on "Extending Schemas" page

When a Time object has microsecond value, the _serialize() method
returns the following string f...

Fix the inconsistency of validates decorator

Remove get_from_dict from extending docs.

make the result of field validators as methods (through validates
decorator) consistent with val...

It does not seem to be supported anymore. Defining a method
"get_attribute" seems to be the corr...

Change the get_value util signature to match built-ins

Always coerce values to string in Decimal object's deserialization method

Deprecated getargspec

Update pyinvoke

Represent nested only and exclude options using dot delimiters

Fix compatibility with pyinvoke 0.13.0

Drop support for Python 2.6

Set dump_only and load_only for Function and Method

...based on values of ``serialize`` and ``deserialize``

closes #328

This reverts commit 862ad1529d0582c640aef66ce7d8342732742b12.

Remove legacy API for 3.0

ref #427

...@error_handler, and @accessor

ref #427

Set child's parent before on_bind_field

- Use SVG badges
- Use readthedocs.io links (https://blog.readthedocs.com/securing-subdomains/)
...

closes #433

Allows for Schema classes to be created dynamically without getting
added to the class registry,...

Pass through exception kwargs

This is to address issues like sloria/webargs#85, where additional arguments
may be passed to Va...

closes #409

made the 'many' param of Nested fields composable with other fields

removed unused attributes from schema base class

Provide nested context in ctor of the nested schema

That way it is made available to nested on_bind_field customizations.

closes #396

closes #401

Report validation errors for each item of List field

Add `equal` parameter in validate.Length

Current implementation of List field does deserialization
in a naive way stopping at first valid...

Schema.validate() should support `partial`