VM Updates (#83)

- Minor fixes to p4runtime exercise and README
- Adding p4runtime/solution
- Adding p4runtime/topology.json
- Updating .gitignore to include solution directory and topology.json
- Fixing root-bootstrap to exit on errors
- Updating VM name in Vagrantfile
- Setting up VM to automatically log 'p4' user in on startup

P4D2_2017_Fall/vm/root-bootstrap.sh

@@ -1,6 +1,7 @@
 #!/bin/bash
 
-set -x
+# Print commands and exit on errors
+set -xe
 
 sudo add-apt-repository ppa:webupd8team/sublime-text-3
 sudo add-apt-repository ppa:webupd8team/atom
@@ -79,3 +80,11 @@ sed -i s@#background=@background=/usr/share/lubuntu/wallpapers/1604-lubuntu-defa
 
 # Disable screensaver
 apt-get -y remove light-locker
+
+# Automatically log into the P4 user
+cat << EOF | tee -a /etc/lightdm/lightdm.conf.d/10-lightdm.conf
+[SeatDefaults]
+autologin-user=p4
+autologin-user-timeout=0
+user-session=Lubuntu
+EOF