Updating rake version in gemspec

[superchilled]

Description

Changing the version of rake specified in the gemspec to 12.3.3.

Note: rake is a development dependency, and so there is no impact on the functionality of the OpenTok-Ruby-SDK gem as a result of this change.

Motivation and Context

This change is prompted by a vulnerability in earlier versions of rake.

How Has This Been Tested?

Not really applicable, since this change is to a development dependency, but ran bundle install to install new version of rake and then used rake to run the spec task in the Rakefile

Example Output or Screenshots (if appropriate):

N/A

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.