Abandon attempts to install Edge; Add Firefox

.drone.yml

@@ -31,7 +31,7 @@ steps:
       packer/windowsserver2019.json
   - |
     packer build \
-      -on-error=abort -timestamp-ui \
+      -on-error=cleanup -timestamp-ui \
       -var-file=packer/variables.vsphere.json \
       -var vm_name=$DRONE_BUILD_NUMBER-${DRONE_COMMIT_SHA:0:10} \
       -var vm_guestos=server2019 \

packer/windowsserver2019.json

@@ -155,7 +155,7 @@
           "choco install -y dotnetfx",
           "choco install -y 7zip.install",
           "choco install -y sysinternals",
-          "choco install -y microsoft-edge --install-arguments=\"ALLOWINSTALL=1\""
+          "choco install -y firefox"
         ],
         "valid_exit_codes":     [0, 3010]
       },