Use openjdk-1.8 packages for Fedora 21

Puppet installs on Fedora 21 fail with:

---
Error: /Stage[main]/Jenkins::Slave/Package[java-1.7.0-openjdk-devel]/ensure:
  change from absent to present failed:
   Execution of '/usr/bin/yum -d 0 -e 0 -y list java-1.7.0-openjdk-devel'
    returned 1: Error: No matching Packages to list
---

Fedora 21 has retired openjdk-1.7 for 1.8; see [1]

[1] http://fedoraproject.org/wiki/Changes/Java8

Change-Id: I06b6d97000f67d099d9886f75f528a41aa68e8e7
Don't use -o argument to "free"

The /bin/free on Fedora 21 doesn't understand -o argument to free;
that being:

---
 -o, --old
   Display the output in old format, the only difference being this
   option will disable the display of the "buffer adjusted" line.
---

i.e. the difference is the "-/+ buffers/cache" line.  Since the sed
only matches on the line starting "^Mem", this is not relevant anyway.

Change-Id: Ib2f763ea82b9a3b397d202453099d58e5dd5a355
Merge "Don't use -o argument to "free""