Merge #627

627: introduce build matrix for rust-1.49 and rust-1.50 r=michaelkirk a=michaelkirk

- [x] I agree to follow the project's [code of conduct](https://github.com/georust/geo/blob/master/CODE_OF_CONDUCT.md).
- [n/a] I added an entry to `CHANGES.md` if knowledge of this change could be valuable to users.
---

Based on georust/docker-images#11


Co-authored-by: Michael Kirk <michael.code@endoftheworl.de>

.github/workflows/test.yml

@@ -1,15 +1,41 @@
 on: push
 name: Run tests
 jobs:
+  # The `ci-result` job doesn't actually test anything - it just aggregates the
+  # overall build status for bors, otherwise our bors.toml would need an entry
+  # for each individual job produced by the job-matrix.
+  #
+  # Ref: https://github.com/rust-lang/crater/blob/9ab6f9697c901c4a44025cf0a39b73ad5b37d198/.github/workflows/bors.yml#L125-L149
+  #
+  # ALL THE SUBSEQUENT JOBS NEED THEIR `name` ADDED TO THE `needs` SECTION OF THIS JOB!
+  ci-result:
+    name: ci result
+    runs-on: ubuntu-latest
+    needs:
+      - geo_types
+      - geo
+      - geo_postgis
+      - coverage
+      - bench
+    steps:
+      - name: Mark the job as a success
+        if: success()
+        run: exit 0
+      - name: Mark the job as a failure
+        if: "!success()"
+        run: exit 1
   geo_types:
     name: geo-types
     runs-on: ubuntu-latest
     if: "!contains(github.event.head_commit.message, '[skip ci]')"
     defaults:
       run:
         working-directory: geo-types
+    strategy:
+      matrix:
+        container_image: ["georust/geo-ci:rust-1.49", "georust/geo-ci:rust-1.50"]
     container:
-      image: georust/geo-ci
+      image: ${{ matrix.container_image }}
     steps:
       - name: Checkout repository
         uses: actions/checkout@v2
@@ -24,8 +50,11 @@ jobs:
     defaults:
       run:
         working-directory: geo
+    strategy:
+      matrix:
+        container_image: ["georust/geo-ci:rust-1.49", "georust/geo-ci:rust-1.50"]
     container:
-      image: georust/geo-ci
+      image: ${{ matrix.container_image }}
     steps:
       - name: Checkout repository
         uses: actions/checkout@v2
@@ -40,8 +69,11 @@ jobs:
     defaults:
       run:
         working-directory: geo-postgis
+    strategy:
+      matrix:
+        container_image: ["georust/geo-ci:rust-1.49", "georust/geo-ci:rust-1.50"]
     container:
-      image: georust/geo-ci
+      image: ${{ matrix.container_image }}
     steps:
       - name: Checkout repository
         uses: actions/checkout@v2

bors.toml

@@ -1,7 +1,3 @@
 status = [
-    "geo-types",
-    "geo",
-    "geo-postgis",
-    "coverage",
-    "bench"
+    "ci result",
 ]