Update Gemfile dependencies

[kevinlind]

Description

Update Gemfile dependencies to their latest. Fixes security vulnerability in addressable v2.7.0 by upgrading to v2.8.0.

Related Issue

Motivation and Context

How Has This Been Tested?

Screenshots (if appropriate):

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:

• I have signed the Adobe Open Source CLA.
• 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.

[codecov]

Codecov Report

Merging #46 (cf781f6) into dev (75216ad) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##              dev      #46   +/-   ##
=======================================
  Coverage   85.99%   85.99%           
=======================================
  Files           5        5           
  Lines         157      157           
=======================================
  Hits          135      135           
  Misses         22       22