ci: use the full vm

.travis.yml

@@ -1,12 +1,15 @@
 language: nix
+# 'vm' means use the full VM, which has 7.5G memory, instead of an LXD
+# container which has "~4G"
+virt: vm
 before_script:
+  # get urbit
   - curl -O https://bootstrap.urbit.org/urbit-v0.10.8-linux64.tgz
   - tar xzf urbit-v0.10.8-linux64.tgz
   - install ./urbit-v0.10.8-linux64/urbit ~/bin
   - export PATH=~/bin:$PATH
   - export PORT=8080
-  # cleanup
-  - find . -name zod -type d -exec rm -rf {} \;
+  # start urbit daemon
   - ./fakezod.sh -d
 script:
   - nix-build