Support for WinRM 1.5+

Allow winrm-elevated elevated runners to work alongside WinRM 1.5+
(now 1.7) Executors.

Only upload the wrapper shell winrm-elevated-shell.ps1 once per connection.
No need to do so on every command request.

Note that a TODO would be to more fully integrate the "elevated runner" with the
"command-executor".

lib/winrm-elevated/runner.rb

@@ -27,6 +27,7 @@ def initialize(winrm_service)
         @winrm_service = winrm_service
         @winrm_file_manager = WinRM::FS::FileManager.new(winrm_service)
         @elevated_shell_path = 'c:/windows/temp/winrm-elevated-shell.ps1'
+        @uploaded            = nil
       end
 
       # Run a command or PowerShell script elevated without any of the
@@ -49,12 +50,14 @@ def powershell_elevated(script, username, password, &block)
       private
 
       def upload_elevated_shell_wrapper_script
+        return if @uploaded
         file = Tempfile.new(['winrm-elevated-shell', 'ps1'])
         begin
           file.write(elevated_shell_script_content)
           file.fsync
           file.close
           @winrm_file_manager.upload(file.path, @elevated_shell_path)
+          @uploaded = true
         ensure
           file.close
           file.unlink

winrm-elevated.gemspec

@@ -25,8 +25,8 @@ Gem::Specification.new do |s|
   s.extra_rdoc_files = %w(README.md LICENSE)
 
   s.required_ruby_version = '>= 1.9.0'
-  s.add_runtime_dependency 'winrm', '~> 1.3'
-  s.add_runtime_dependency 'winrm-fs', '~> 0.2.2'
+  s.add_runtime_dependency 'winrm', '~> 1.7'
+  s.add_runtime_dependency 'winrm-fs', '~> 0.3.0'
   s.add_development_dependency 'rspec', '~> 3.2'
   s.add_development_dependency 'rake', '~> 10.3'
   s.add_development_dependency 'rubocop', '~> 0.28'