(maint) Fix kernel major version fact name.

The fact name cfacter was using was "kernelmajrelease".  The correct
fact name is "kernelmajversion".
(CFACT-22) Add missing domain and fqdn facts to networking resolver.

Adding the domain and fqdn facts to the networking resolver.
Merge pull request #21 from peterhuene/maint/kernelfix

(maint) Fix kernel major version fact name.
Merge pull request #18 from peterhuene/facts/networking

(CFACT-22) Add missing domain and fqdn facts to networking resolver.
(maint) Remove vendor libraries in favor of find_package.

Removing Boost, log4cxx, and RE2 from the vendor directory. Instead, use
find_package to locate pre-existing binary packages.
(CFACT-8) Add unit test framework.

Adding gmock to vendor directory.
Building a test executable for libfacter.
Implementing, at first, unit test for string utility functions.
Adding tests to travis CI.
(cfact-21) Add uptime facts back