Add migrate to docker

With these changes, those who might want to execute migrations on other containers will be able to since all necessary files are available in the docker image

Dockerfile

@@ -11,16 +11,20 @@ RUN go mod download
 
 COPY . .
 RUN make build
+RUN CGO_ENABLED=0 GOOS=linux go build -pkgdir=$GOPATH/pkg/mod/ -tags 'postgres' -o bin/migrate \
+	github.com/golang-migrate/migrate/v4/cmd/migrate
 
 FROM alpine:3.10
 
 RUN apk add --no-cache ca-certificates
-  
+
 WORKDIR /app
 
 COPY --from=build-env /Will.IAM/bin/Will.IAM /app
 COPY --from=build-env /Will.IAM/config /app/config
 COPY --from=build-env /Will.IAM/assets /app/assets
+COPY --from=build-env /Will.IAM/migrations /app/postgres/migrations
+COPY --from=build-env /Will.IAM/bin/migrate /app/postgres
 
 EXPOSE 4040