v1.4.0 dbt_github

PR #80 includes the following updates:

Under the Hood

• Migrates the union_connections, apply_source_relation, and partition_by_source_relation macros to the dbt_fivetran_utils package.
• Adds the fivetran_using_source_casing variable for case-sensitive destination support. When enabled, downstream transformations respect source casing to ensure consistent results. See the Additional Configurations section of the README for details.

Full Changelog: v1.3.0...v1.4.0