Add git2jss, machammer, and Frevo

Upstream PRs:
- timsutton#18
- timsutton#23
- timsutton#25

Author: homebysix

Diff for: README.md

@@ -78,6 +78,7 @@ Table of Contents
 * [appleLoops](https://github.com/carlashley/appleLoops) - Utility for downloading essential and optional audio content for Apple GarageBand, Logic Pro X, and MainStage 3.
 * [JSSImporter](https://github.com/sheagcraig/JSSImporter) - Framework for connecting AutoPkg to JSS, for administrators running JAMF's Casper Suite.
 * [JSSRecipeCreator](https://github.com/sheagcraig/JSSRecipeCreator) - Tool that enables Casper administrators to quickly create JSSImporter-compatible AutoPkg recipes.
+* [git2jss](https://github.com/BadStreff/git2jss) - Easily sync your scripts and extension attributes from a git repo to the JSS 
 * [MacNamer](https://github.com/grahamgilbert/macnamer) - Combination of a Django web app and a companion script to run on client Macs for automatically setting computer names.
 * [make-adobe-cc-license-pkg](https://github.com/timsutton/make-adobe-cc-license-pkg) - Tool for building packages and Munki pkginfos for CC for Teams device and Enterprise serial licenses.
 * [make-profile-pkg](https://github.com/timsutton/make-profile-pkg) - Convert a Configuration Profile to an installer package that can be installed to both booted and non-booted volumes.
@@ -122,6 +123,7 @@ Table of Contents
 * [Stethoscope](https://github.com/Netflix/Stethoscope) - Web application that collects information for a given user's devices and gives them clear and specific recommendations for securing their systems.
 * [U. of Utah Marriott Library Management Tools](https://github.com/univ-of-utah-marriott-library-apple/management_tools) - Python module for client management.
 * [Zentral](https://github.com/zentralopensource/zentral) - Framework that allows administrators to configure automatic actions based on changes detected by [osquery](https://osquery.io/).
+* [machammer](https://github.com/filipp/machammer) - library for Mac client management.
 
 ## Mobile Device Management (MDM)
 
@@ -150,6 +152,7 @@ Table of Contents
 * [py-gsxws](https://github.com/filipp/py-gsxws) - Library for communicating with Apple's GSX API
 * [SimplePySSH](https://github.com/robperc/SimplePySSH) - Module for executing and reading output from simple shell commands on remote machines via SSH using only built-in modules.
 * [precache](https://github.com/krypted/precache) - Used to cache available Apple updates into an OS X Server running the Caching Service.
+* [Frevo](https://github.com/matuzalemmuller/Frevo) - Run customizable commands from the Mac top bar.
 * [python-jamf](https://github.com/univ-of-utah-marriott-library-apple/python-jamf) - Module to access the Jamf Pro Classic API.
 * [jctl](https://github.com/univ-of-utah-marriott-library-apple/jctl) - Command line based tool that provides easy access to the Jamf management capabilities of [python-jamf](https://github.com/univ-of-utah-marriott-library-apple/python-jamf).