changing ip_address param to expect list

[daarrn]

Description

changing spec options, ip_address parameter is being changed from a 'str' type to a 'list' type

fixes issue #245

How Has This Been Tested?

validated the change using a local collection of lowlydba and was able to successfully create a multi subnet ag listener when the ip_address parameter was expecting a list

Types of changes

• [x ] Bug fix (non-breaking change which fixes an issue) - Fixes #
• [ ] New feature (non-breaking change which adds functionality)

Checklist:

• [x ] I have read/followed the CONTRIBUTING document.
• [x ] I have read/followed the PR Quick Start Guide
• [x ] I have added tests to cover my changes or they are N/A.
• [x ] I have added a changelog fragment describing the changes.
• [ ] New module options/parameters include a version_added property.