Add platform specifiers (vapor#89)

* Add platform specifiers

* De-ancientize CI

Author: gwynne

.github/workflows/test.yml

@@ -1,44 +1,10 @@
 name: test
-on: { pull_request: {} }
+on:
+  pull_request: { branches: ['*'] }
+  push: { branches: ['main'] }
 
 jobs:
-  getcidata:
-    runs-on: ubuntu-latest
-    outputs:
-      environments: ${{ steps.output.outputs.environments }}
-    steps:
-      - id: output
-        run: |
-          envblob="$(curl -fsSL https://raw.githubusercontent.com/vapor/ci/main/pr-environments.json | jq -cMj '.')"
-          echo "::set-output name=environments::${envblob}"
-
-  test-vapor:
-    needs: getcidata
-    strategy:
-      fail-fast: false
-      matrix:
-        env: ${{ fromJSON(needs.getcidata.outputs.environments) }}
-    runs-on: ${{ matrix.env.os }}
-    container: ${{ matrix.env.image }}
-    steps:
-      - name: Select toolchain
-        uses: maxim-lobanov/[email protected]
-        with:
-          xcode-version: ${{ matrix.env.toolchain }}
-        if: ${{ matrix.env.toolchain != '' }}
-      - name: Check out Vapor
-        uses: actions/checkout@v3
-      - name: Run tests with Thread Sanitizer
-        timeout-minutes: 20
-        run: swift test --enable-test-discovery --sanitize=thread
-
-  test-exports:
-       name: Test exports
-       runs-on: ubuntu-latest
-       steps:
-         - name: Check out source
-           uses: actions/checkout@v3
-           with:
-             fetch-depth: 0
-         - name: Build
-           run: swift build -Xswiftc -DBUILDING_DOCC
+  unit-tests:
+    uses: vapor/ci/.github/workflows/run-unit-tests.yml@reusable-workflows
+    with:
+      with_coverage: false

Package.swift

@@ -3,6 +3,12 @@ import PackageDescription
 
 let package = Package(
     name: "multipart-kit",
+    platforms: [
+        .macOS(.v10_15),
+        .iOS(.v13),
+        .tvOS(.v13),
+        .watchOS(.v6),
+    ],
     products: [
         .library(name: "MultipartKit", targets: ["MultipartKit"]),
     ],