Refactor imports, Add vendor/ as submodule (#5)

refact imports to github.xxx. update go.mod + go.sum

* removed vendor/ folder

* Added vendor/ submodule.

Moved dependencies that need to be vendored into separate repository.
	- https://github.com/spdfg/elektron-vendor
Added vendor/ as a submodule using the below command.
	- git submodule add https://github.com/spdfg/elektron-vendor vendor
If wanting to use vendor, run the following commands after cloning
elektron.
1. git submodule init
2. git submodule update

* added instructions to clone vendor/ submodule.

* updated module to spdfg. Refactored imports

scripts/RAPL_PKG_Throttle.py

@@ -1,5 +1,5 @@
 #!/usr/bin/python3
-# Copyright (C) 2018 spdf
+# Copyright (C) 2018 spdfg
 # 
 # This file is part of Elektron.
 #