Verify accuracy of Gemfile.lock description

[Ilya Zarembsky]

The lesson text offers this explanation for the Gemfile.lock file: "The lock word is actually because it makes sure that only one thing is running bundle install at a time." This comes across as incorrect/misleading given that the purpose of the lock file is to document and enforce a specific working gem versions configuration.

[Jason Decker]

Hi there,

Thank you for bringing this to our attention. We corrected the Gemfile.lock definition.

Aas always thank you for contributing.