Version 0.15.0 alpha 15

• chore(call): resolve VCF reference path
• fix(call): issue with consensus fallback
• fix(call): bug with terminating progress worker
• chore(call): log # get_repeat_count iters
• chore(call): more specific debug log when outputting VCF

Full Changelog: v0.15.0-alpha.14...v0.15.0-alpha.15