Add workflow_dispatch trigger for manual runs. #70

Job	Run time
deploy-blue / terraform-plan	31s
deploy-green / terraform-plan	45s
deploy-blue / terraform-apply	2m 31s
deploy-green / terraform-apply	2m 14s
deploy-green / e2e-tests	1m 43s
deploy-blue / e2e-tests	-1s
deploy-green / terraform-apply	1m 42s
deploy-green / terraform-plan	45s
deploy-blue / terraform-plan	31s
deploy-blue / terraform-apply	2m 31s
deploy-blue / e2e-tests	-166s
deploy-green / e2e-tests	49s
	11m 15s

Provide feedback