add a hint
add hint/link to related stack overflow problem
fix typo
Remove trailing whitespace
Added test for Hash default value. Developers often forget about using it.
Fix a typo in a method name.
Fixed test_you_can_get_a_single_character_from_a_string for multiple rubies (1.8, 1.9)
Fixed missed test case.
Fix typo of subclasses (from subcases)
Adding missing assert in iteration test.

Also checking against symbol rather than string.
Typos.
Merge pull request #43 from rtlechow/master

Just some typos.
Merge pull request #42 from kowen/master

Adding missing assert in iteration test.
Merge pull request #36 from dcoder2099/master

Fixed a typo in about_inheritance.rb
Merge pull request #35 from TheSeparateFirst/master

Fixed about_strings for multiple rubies
Merge pull request #31 from erickt/master

Just a small typo
Merge pull request #30 from greyblake/master

Hash default value
Merge pull request #28 from alindeman/master

Remove Trailing Whitespace
Merge pull request #28 from alindeman/master

Remove Trailing Whitespace
Merge pull request #25 from kimptoc/master

Some minor tweaks