[mod1-02] updated to 2018 class
[mod1-02] updated to 2018 class

* switch to 2018 theme
* added "Syntax Check"
* remove creating user on linux
* added "Reload and Reset"
* rephrased subnet mask first mention
* removed "Ethernet Basics"
* remove ping/loopback

hlcs/advanced-networking,hlcs/advanced-networking