Make the TypeExtrasHandler more robust

Ruby 2.7's AST has added an entry for `:period` between the function
call and the const reference. This change makes it so the method1_name parsing can deal with that.

Ruby 2.5:
```
[1] pry(#<PuppetStrings::Yard::Handlers::Ruby::TypeExtrasHandler>)> statement[0].children
=> [s(:const_path_ref,
    s(:var_ref, s(:const, "Puppet", line: 1..1, source: 2..7), line: 1..1, source: 2..7),
    s(:const, "Type", line: 1..1, source: 10..13),
    line: 1..1,
    source: 2..13),
 s(:ident, "type", line: 1..1, source: 15..18),
 s(:arg_paren,
    s(s(:symbol_literal, s(:symbol, s(:ident, "file", line: 1..1, source: 21..24), line: 1..1, source: 20..24), line: 1..1, source: 20..24), false),
    line: 1..1,
    source: 19..25)]
[2] pry(#<PuppetStrings::Yard::Handlers::Ruby::TypeExtrasHandler>)>
```

Ruby 2.7:
```
[4] pry(#<PuppetStrings::Yard::Handlers::Ruby::TypeExtrasHandler>)> statement[0].children
=> [s(:const_path_ref,
    s(:var_ref, s(:const, "Puppet", line: 1..1, source: 2..7), line: 1..1, source: 2..7),
    s(:const, "Type", line: 1..1, source: 10..13),
    line: 1..1,
    source: 2..13),
 s(:period, ".", line: 1..1, source: 14..14),
 s(:ident, "type", line: 1..1, source: 15..18),
 s(:arg_paren,
    s(s(:symbol_literal, s(:symbol, s(:ident, "file", line: 1..1, source: 21..24), line: 1..1, source: 20..24), line: 1..1, source: 20..24), false),
    line: 1..1,
    source: 19..25)]
[5] pry(#<PuppetStrings::Yard::Handlers::Ruby::TypeExtrasHandler>)>
```

Author: DavidS

lib/puppet-strings/yard/handlers/ruby/type_extras_handler.rb

@@ -32,7 +32,7 @@ class PuppetStrings::Yard::Handlers::Ruby::TypeExtrasHandler < PuppetStrings::Ya
 
     return unless (statement.count > 1) && (statement[0].children.count > 2)
     module_name = statement[0].children[0].source
-    method1_name = statement[0].children[1].source
+    method1_name = statement[0].children.drop(1).find{ |c| c.type == :ident }.source
     return unless (module_name == 'Puppet::Type' || module_name == 'Type') && method1_name == 'type'
 
     typename = get_name(statement[0], 'Puppet::Type.type')