Update the FreeBSD CI image to an 11.3 snapshot

11.2 is EOL.

Author: asomers

.cirrus.yml

@@ -1,12 +1,12 @@
 freebsd_instance:
-  image: freebsd-11-2-release-amd64
+  image_family: freebsd-11-3-snap
 
 # Test FreeBSD in a full VM on cirrus-ci.com.  Test the i686 target too, in the
 # same VM.  The binary will be built in 32-bit mode, but will execute on a
 # 64-bit kernel and in a 64-bit environment.  Our tests don't execute any of
 # the system's binaries, so the environment shouldn't matter.
 task:
-  name: FreeBSD 11.2
+  name: FreeBSD 11.3
   cargo_cache:
     folder: $CARGO_HOME/registry
     fingerprint_script: cat Cargo.lock || echo ""

bors.toml

@@ -1,6 +1,6 @@
 # Gate on Travis CI and Buildbot
 status = ["continuous-integration/travis-ci/push",
-	  "FreeBSD 11.2"]
+	  "FreeBSD 11.3"]
 
 # Set bors's timeout to 4 hours
 #