packer: Make names consistent with the files and purpose.

packer/centos-6.7-vm-boostrap.json

@@ -9,7 +9,7 @@
     "builders":
     [
         {
-            "name": "centos68-slapos",
+            "name": "centos68-vm-bootstrap",
 
             "type": "qemu",
             "format": "qcow2",

packer/centos-7.2-vm-bootstrap.json

@@ -9,7 +9,7 @@
     "builders":
     [
         {
-            "name": "centos72-slapos",
+            "name": "centos72-vm-bootstrap",
 
             "type": "qemu",
             "format": "qcow2",

packer/debian7-vm-bootstrap.json

@@ -9,7 +9,7 @@
     "builders":
     [
         {
-            "name": "debian7-slapos",
+            "name": "debian7-vm-bootstrap",
 
             "type": "qemu",
             "format": "qcow2",

packer/debian8-vm-boostrap.json

@@ -9,7 +9,7 @@
     "builders":
     [
         {
-            "name": "debian8-slapos",
+            "name": "debian8-vm-bootstrap",
 
             "type": "qemu",
             "format": "qcow2",

packer/debian8-webrunner-standalone.json

@@ -9,7 +9,7 @@
     "builders":
     [
         {
-            "name": "debian8",
+            "name": "debian8-webrunner",
 
             "type": "qemu",
             "format": "qcow2",

packer/ubuntu-14.04-server-amd64-vm-bootstrap.json

@@ -8,7 +8,7 @@
     "builders":
     [
         {
-            "name": "ubuntu-14-04-server-slapos",
+            "name": "ubuntu-14-04-server-vm-bootstrap",
 
             "type": "qemu",
             "format": "qcow2",

packer/ubuntu-15.04-server-amd64-vm-bootstrap.json

@@ -8,12 +8,13 @@
     "builders":
     [
         {
-            "name": "ubuntu-15-04-server-slapos",
+            "name": "ubuntu-15-04-server-vm-bootstrap",
 
             "type": "qemu",
             "format": "qcow2",
             "accelerator": "kvm",
             "disk_size": "{{ user `disk_size`}}",
+            "headless": true,
 
             "iso_url": "http://releases.ubuntu.com/15.04/ubuntu-15.04-server-amd64.iso",
             "iso_checksum": "487f4a81f22f8597503db3d51a1b502e",