Tag conformance tests with a [Conformance] string in the description

- remove skip list from conformance-test.sh and filter by the new tag
- remove experimental api tests from conformance test suite
- remove all tests from conformance test suite which are either
  restricted to e.g. gce, gke, aws or require SSH

test/e2e/service_accounts.go

@@ -34,7 +34,7 @@ import (
 var _ = Describe("ServiceAccounts", func() {
 	f := NewFramework("svcaccounts")
 
-	It("should mount an API token into pods", func() {
+	It("should mount an API token into pods [Conformance]", func() {
 		var tokenName string
 		var tokenContent string
 		var rootCAContent string