Update Dockerfile for crystal 1.0

docker/Dockerfile

@@ -1,4 +1,4 @@
-FROM crystallang/crystal:0.36.1-alpine AS builder
+FROM crystallang/crystal:1.0.0-alpine AS builder
 RUN apk add --no-cache curl sqlite-static yaml-static
 WORKDIR /invidious
 COPY ./shard.yml ./shard.yml