Create host (#276)

* Change testHostCatalog methods to be like other resource test methods

* Implement CreateHost

* Make allocHost return a pointer to a Host

internal/host/static/host_set_test.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/hashicorp/boundary/internal/db"
 	"github.com/hashicorp/boundary/internal/host/static/store"
+	"github.com/hashicorp/boundary/internal/iam"
 	"github.com/jinzhu/gorm"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
@@ -13,7 +14,8 @@ import (
 
 func TestHostSet_New(t *testing.T) {
 	conn, _ := db.TestSetup(t, "postgres")
-	cat := testCatalog(t, conn)
+	_, prj := iam.TestScopes(t, conn)
+	cat := testCatalog(t, conn, prj.PublicId)
 
 	conn.LogMode(false)
 	type args struct {