Convert tests to use plain rspec-puppet

Tests in the new style produces the following documentation output:

abs
  should not eq nil
  should run abs() and raise an Puppet::ParseError
  should run abs(-34) and return 34
  should run abs("-34") and return 34
  should run abs(34) and return 34
  should run abs("34") and return 34

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/puppet/parser/functions/member.rb b/lib/puppet/parser/functions/member.rb
index 88609ce..1e5b3de 100644
--- a/lib/puppet/parser/functions/member.rb
+++ b/lib/puppet/parser/functions/member.rb
@@ -44,7 +44,7 @@ would return: false
     end
 
     if arguments[1].is_a? String or arguments[1].is_a? Fixnum
-      item = Array(arguments[1])
+      item = [arguments[1]]
     else
       item = arguments[1]
     end