Add Windows support to the system verification check

Pulled SysSpecs out of types.go and created two os specific implementations with build tags

Similarly created conditionally compiled implementations of KernelValidationHelper to get Kernel version in os specific manner, as well as os specific docker endpoints (socket vs named pipes)

test/e2e_node/system/kernel_validator_helper.go

@@ -0,0 +1,23 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package system
+
+// KernelValidatorHelper is an interface intended to help with os specific kernel validation
+type KernelValidatorHelper interface {
+	// GetKernelReleaseVersion gets the current kernel release version of the system
+	GetKernelReleaseVersion() (string, error)
+}