security/ruby-rex-powershell: update to 0.1.77

0.1.77 2017/09/23

* Convert double quotes to single quotes to match #{URL}

0.1.76 2017/09/07

* Merge pull request #9 from sempervictus/feature-payload_msil_jit

0.1.75 2017/08/25

* Remove useless failing spec

* Improve use of RandomIdentifier::Generator
* Add MSIL to template constants
* Update spec for MSIL payload
* Implement MSIL payload in Rex gem via template
* Update spec for command
* Finalize quote wrapper
* Rework quote handling
* Cleanup Command single quotes redundant gsub

0.1.74 2017/07/18

* Alternative to IEX in dl_and_exec_string methods
* Command spec - deal with :use_single_quotes
* Output and command improvements for Win10

0.1.73 2017/05/12

* update spec to require Ruby 2.2.0 or greater

(taca)