Update CircleCI image and config

.circleci/Dockerfile

@@ -1,4 +1,4 @@
-FROM debian:stretch
+FROM debian:buster
 
 RUN apt-get -qq update \
   && apt-get install -y --no-install-recommends bash ca-certificates build-essential \
@@ -12,7 +12,7 @@ RUN \
   mkdir /root/vips \
   && cd /root/vips \
   && curl -s -S -L -o vips_releases.json "https://api.github.com/repos/libvips/libvips/releases" \
-  && for VIPS_VERSION in "8.6" "8.7" "8.8"; do \
+  && for VIPS_VERSION in "8.7" "8.8" "8.9"; do \
     mkdir $VIPS_VERSION \
     && export VIPS_RELEASE=$(grep -m 1 "\"tag_name\": \"v$VIPS_VERSION." vips_releases.json | sed -E 's/.*"v([^"]+)".*/\1/') \
     && echo "Building Vips $VIPS_RELEASE as $VIPS_VERSION" \

.circleci/config.yml

@@ -8,62 +8,62 @@ workflows:
       - lint:
           requires:
             - checkout_code
-          go_version: "1.13"
-          vips_version: "8.8"
+          go_version: "1.14"
+          vips_version: "8.9"
       - build:
-          name: go1.13_vips8.8
+          name: go1.14_vips8.9
           requires:
             - checkout_code
-          go_version: "1.13"
+          go_version: "1.14"
+          vips_version: "8.9"
+      - build:
+          name: go1.14_vips8.8
+          requires:
+            - checkout_code
+          go_version: "1.14"
           vips_version: "8.8"
       - build:
-          name: go1.13_vips8.7
+          name: go1.14_vips8.7
           requires:
             - checkout_code
-          go_version: "1.13"
+          go_version: "1.14"
           vips_version: "8.7"
       - build:
-          name: go1.13_vips8.6
+          name: go1.13_vips8.9
           requires:
             - checkout_code
           go_version: "1.13"
-          vips_version: "8.6"
+          vips_version: "8.9"
       - build:
-          name: go1.12_vips8.8
+          name: go1.13_vips8.8
           requires:
             - checkout_code
-          go_version: "1.12"
+          go_version: "1.13"
           vips_version: "8.8"
       - build:
-          name: go1.12_vips8.7
+          name: go1.13_vips8.7
           requires:
             - checkout_code
-          go_version: "1.12"
+          go_version: "1.13"
           vips_version: "8.7"
       - build:
-          name: go1.12_vips8.6
+          name: go1.12_vips8.9
           requires:
             - checkout_code
           go_version: "1.12"
-          vips_version: "8.6"
+          vips_version: "8.9"
       - build:
-          name: go1.11_vips8.8
+          name: go1.12_vips8.8
           requires:
             - checkout_code
-          go_version: "1.11.13"
+          go_version: "1.12"
           vips_version: "8.8"
       - build:
-          name: go1.11_vips8.7
+          name: go1.12_vips8.7
           requires:
             - checkout_code
-          go_version: "1.11.13"
+          go_version: "1.12"
           vips_version: "8.7"
-      - build:
-          name: go1.11_vips8.6
-          requires:
-            - checkout_code
-          go_version: "1.11.13"
-          vips_version: "8.6"
 
 executors:
   imgproxy: