Remove python version specific requirements

Since PR avocado-framework/avocado#1029
is trying to merge python version specific requirements files.
We don't need to specify another requirements when running on
python 2.6.

Change-Id: I9cf885df10b036a59f3d2587f212826e4219fd94
Signed-off-by: Hao Liu <hliu@redhat.com>

projects/test-runner/runner

@@ -834,8 +834,6 @@ if __name__ == '__main__':
             os.chdir('../avocado-vt')
             logging.info("Installing required packages for avocado-vt")
             os.system("pip install -r requirements.txt --upgrade")
-            if sys.version_info[1] == 6:
-                os.system("pip install -r requirements-travis-python26.txt --upgrade")
             tp_path = os.path.realpath('../tp-libvirt')
             os.system('sed -i "s \\S*github.com/autotest/tp-libvirt.git '
                       '%s g" test-providers.d/*' % tp_path)
@@ -848,8 +846,6 @@ if __name__ == '__main__':
             os.chdir(working_dir)
             logging.info("Install required packages for avocado")
             os.system("pip install -r requirements.txt --upgrade")
-            if sys.version_info[1] == 6:
-                os.system("pip install -r requirements-travis-python26.txt --upgrade")
 
             logging.info("Installing avocado")
             os.symlink('../avocado-vt/virttest', 'virttest')