Change all Py2 style class definition to Py3 style

[haifeng-jin]

Change all occurance of class SomeClass(object): to class SomeClass: throughout the codebase.
This is the recommended style in Python 3.
More details.

For example, this:

keras-tuner/keras_tuner/engine/stateful.py

Line 22 in a7a361f

class Stateful(object):

needs to be changed to:

class Stateful:

Please comment on this issue before you start working on it so that others can know.

[LuNoX]

Similar to #813, this looks like a very doable issue and I would like to take it on as well, if that's ok :)

[haifeng-jin]

@LuNoX Of course. Thanks!

[LuNoX]

I opened a PR for the changes: #815.
I hope this is what you were looking for :)

[LuNoX]

For future reference, if similar issues arise:

I made the changes using a RegEx.
(class .*)\(object\): finds any sequence of characters that looks like "class <SomeCharacters>(object):" and captures "class <SomeCharacters>". You can then replace all matches with $1: which translates to "class <SomeCharacters>:".

Hope this helps :)