Rename history.md to CHANGELOG.md

[mxygem]

Summary

Renaming History.md to CHANGELOG.md in accordance with cucumber/cucumber 251

Motivation and Context

Working to normalize documents across the various repos.

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 not work as expected)
• Refactoring (cleanup of codebase withouth changing any existing functionality)
• Update documentation

Checklist:

• I've added tests for my code
• My change requires a change to the documentation.
• I have updated the documentation accordingly.

[mxygem]

When some other details are ironed out, the existing CHANGELOG file will be updated for the day forward formatting from Keep a Changelog.

[maxmeyer]

@jaysonesmith Thanks

[mxygem]

@maxmeyer You're welcome! There's more to come.