Chapter 3, Lesson 2 accepts invalid Ruby

[gmarndt]

In Chapter 3, Lesson 2, one of the examples (string_start_with) accepts a call to "starts_with?" as correct. The correct method is "start_with?". For example...

# This is accepted by the lesson, even though starts_with? is not valid Ruby.
"Ruby is a beautiful language".starts_with? "Ruby"

# This is also accepted by the lesson, correctly.
"Ruby is a beautiful language".start_with? "Ruby"