Raise TypeError from #singleton_class
Allow instance_exec for Symbol and Numeric
Disallow singleton methods for Symbol and Numeric
Numeric#singleton_method_added

Specs untagged:

Numeric#singleton_method_added
- raises a TypeError when trying to define a singleton method on a Numeric
Forbid extnding Fixnum ans Symbol Objects
We cann't use #exnted
fix Array#values_at
Merge pull request #723 from kostya/values_at

fix Array#values_at
random change (kick buildbot)
Module#(public_|)instance_methods
Name the unused argument
Use None as values, defer calling newsymbol
tag some new specs
Merge pull request #724 from jstepien/instance_methods

Module#(public_|)instance_methods
Untagged some specs
Merge pull request #725 from jstepien/untagging

Untagged some specs
Module#define_singleton_method
Extract create_and_define_method  from ModuleObject
Remove the extra arg, simplify define_(singleton_)method
Merge pull request #726 from jstepien/define_singleton_method

Module#define_singleton_method