Machine init --provider

Add the ability for users to override the default provider when creating mahcines.  The new flag is `--provider` and allows you to specifiy a valid vmtype for the platform.  This PR also removes the previous list test where we tested listing all providers.  I added a PR for testing --provider which includes a standard `machine ls` which defaults now to showing all providers.

Signed-off-by: Brent Baude <bbaude@redhat.com>

pkg/machine/e2e/config_init_test.go

@@ -10,22 +10,8 @@ import (
 )
 
 type initMachine struct {
-	/*
-	      --cpus uint              Number of CPUs (default 1)
-	      --disk-size uint         Disk size in GiB (default 100)
-	      --ignition-path string   Path to ignition file
-	      --username string        Username of the remote user (default "core" for FCOS, "user" for Fedora)
-	      --image-path string      Path to bootable image (default "testing")
-	  -m, --memory uint            Memory in MiB (default 2048)
-	      --now                    Start machine now
-	      --rootful                Whether this machine should prefer rootful container execution
-	      --playbook string        Run an ansible playbook after first boot
-	      --tls-verify             Require HTTPS and verify certificates when contacting registries
-	      --timezone string        Set timezone (default "local")
-	  -v, --volume stringArray     Volumes to mount, source:target
-	      --volume-driver string   Optional volume driver
-	*/
 	playbook           string
+	provider           string
 	cpus               *uint
 	diskSize           *uint
 	swap               *uint
@@ -80,6 +66,9 @@ func (i *initMachine) buildCmd(m *machineTestBuilder) []string {
 	if l := len(i.playbook); l > 0 {
 		cmd = append(cmd, "--playbook", i.playbook)
 	}
+	if l := len(i.provider); l > 0 {
+		cmd = append(cmd, "--provider", i.provider)
+	}
 	if i.userModeNetworking {
 		cmd = append(cmd, "--user-mode-networking")
 	}
@@ -176,6 +165,11 @@ func (i *initMachine) withRunPlaybook(p string) *initMachine {
 	return i
 }
 
+func (i *initMachine) withProvider(p string) *initMachine {
+	i.provider = p
+	return i
+}
+
 func (i *initMachine) withTlsVerify(tlsVerify *bool) *initMachine {
 	i.tlsVerify = tlsVerify
 	return i