Allow network names to be strings in V1 config

CHANGELOG.md

@@ -16,6 +16,8 @@ IMPROVEMENTS:
     systems. [GH-1671]
   - More precise detection of Ubuntu/Debian guests so that running Vagrant
     within an LXC container works properly now.
+  - Allow strings in addition to symbols to more places in V1 configuration
+    as well as V2 configuration.
 
 BUG FIXES:
 

plugins/kernel_v1/config/vm.rb

@@ -53,6 +53,9 @@ module VagrantPlugins
       end
 
       def network(type, *args)
+        # Convert to symbol so we can allow most anything...
+        type = type.to_sym if type
+
         if type == :hostonly
           @networks << [:private_network, args]
         elsif type == :bridged