Update .cirrus.yml (#133)

Author: amontoison

.cirrus.yml

@@ -1,15 +1,25 @@
-freebsd_instance:
-  image: freebsd-12-1-release-amd64
 task:
-  name: FreeBSD
-  env:
-    matrix:
-      - JULIA_VERSION: 1.6
-      - JULIA_VERSION: 1
-      - JULIA_VERSION: nightly
-  allow_failures: $JULIA_VERSION == 'nightly'
-  install_script:
-    - sh -c "$(fetch https://raw.githubusercontent.com/ararslan/CirrusCI.jl/master/bin/install.sh -o -)"
+  matrix:
+    - name: FreeBSD
+      freebsd_instance:
+        image_family: freebsd-13-3
+      env:
+        matrix:
+          - JULIA_VERSION: 1
+  install_script: |
+    URL="https://raw.githubusercontent.com/ararslan/CirrusCI.jl/master/bin/install.sh"
+    set -x
+    if [ "$(uname -s)" = "Linux" ] && command -v apt; then
+        apt update
+        apt install -y curl
+    fi
+    if command -v curl; then
+        sh -c "$(curl ${URL})"
+    elif command -v wget; then
+        sh -c "$(wget ${URL} -q -O-)"
+    elif command -v fetch; then
+        sh -c "$(fetch ${URL} -o -)"
+    fi
   build_script:
     - cirrusjl build
   test_script: