Updates image targets to match CI (#50)

We only build and distribute amd64 images at this time, so we should
specify that as the platform when building the image to prevent
accidental pushes of arm64 images when building from Apple Silicon.

Additionally, CI doesn't publish images with the `v` prefix, so the
versioning targets are updated to match.

Author: apmatthews

Makefile

@@ -15,12 +15,12 @@ list-images:
 	docker images $(IMAGE_NAME) -a
 
 build:
-	docker build --no-cache -t $(IMAGE) ./
+	docker build --platform linux/amd64 --no-cache -t $(IMAGE) ./
 
 version: build
-	docker image tag $(IMAGE) $(IMAGE_NAME):v$(MAJOR_VERSION) && \
-	docker image tag $(IMAGE) $(IMAGE_NAME):v$(MAJOR_VERSION).$(MINOR_VERSION) && \
-	docker image tag $(IMAGE) $(IMAGE_NAME):v$(MAJOR_VERSION).$(MINOR_VERSION).$(PATCH_VERSION)
+	docker image tag $(IMAGE) $(IMAGE_NAME):$(MAJOR_VERSION) && \
+	docker image tag $(IMAGE) $(IMAGE_NAME):$(MAJOR_VERSION).$(MINOR_VERSION) && \
+	docker image tag $(IMAGE) $(IMAGE_NAME):$(MAJOR_VERSION).$(MINOR_VERSION).$(PATCH_VERSION)
 
 test-unit:
 	./tests/test_functions.sh