sudo apt-get upgrade is not upgrading packages
hp@hp-HP-15-Notebook-PC:~$ sudo apt-get upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
The following packages have been kept back:
libnss3 openjdk-7-jdk openjdk-7-jre openjdk-7-jre-headless thunderbird
thunderbird-gnome-support
0 upgraded, 0 newly installed, 0 to remove and 6 not upgraded.
hp@hp-HP-15-Notebook-PC:~$
