require requests >= 1.0, requests-kerberos

Change-Id: Iabaecb95658ee22744e6c24447aba87ebd60ba36
tests: //head/title does not work in Selenium 2.33

    FAIL: bkr.inttest.server.selenium.test_external_reports:ExternalReportTest.test_can_delete
      /usr/bin/vim +38 src/bkr/inttest/server/selenium/test_external_reports.py  # test_can_delete
        'External Reports')
    AssertionError: u'' != 'External Reports'

Change-Id: I29983d30e1a1727eb8e6d0d03295fae574e26109
tests: default to hardcoded nonexistent lab controller

The problem with using LabController.query.first() is that, in the
dogfood task, the first lab controller is actually real (it's the lab
controller participating in the tests) and so we end up creating
hundreds of junk power commands which beaker-provision will try to
execute. In itself that isn't harmful, but it makes beaker-provision
fall behind on executing the *real* commands that we want it to run in
the bkr.inttest.labcontroller.test_provision module.

Change-Id: Ifee75ef88126fc6cc8adc1ead866f7f0493bd0f0
Merge changes Ifee75ef8,I29983d30,Iabaecb95 into develop

* changes:
  tests: default to hardcoded nonexistent lab controller
  tests: //head/title does not work in Selenium 2.33
  require requests >= 1.0, requests-kerberos