Switch to rust:1.X images

hcpl · hcpl · commit 71c1bea72ef6 · 2018-04-04T19:02:37.000+03:00
As per https://hub.docker.com/r/jimmycuadra/rust/ images there are deprecated now.
diff --git a/circle.yml b/circle.yml
@@ -3,7 +3,7 @@ jobs:
   build:
     working_directory: ~/build
     docker:
-      - image: jimmycuadra/rust:1.20.0
+      - image: rust:1.20.0
       - image: postgres:9.6
         environment:
           POSTGRES_PASSWORD: password
