Check whether pod matches the inter-pod anti-affinity of another Pod in a given Node in NodeFit() (#1356)

* Check if Pod matches inter-pod anti-affinity of other pod on node as part of NodeFit()

* Add unit tests for checking inter-pod anti-affinity match in NodeFit()
* Export setPodAntiAffinity() helper func to test utils

* Add docs for inter-pod anti-affinity in README

* Refactor logic for inter-pod anti-affinity to use in multiple pkgs
* Move logic for finding match between pods with antiaffinity out of framework to reuse in other pkgs
* Move interpod antiaffinity funcs to pkg/utils/predicates.go

* Add unit tests for inter-pod anti-affinity check
* Test logic in GroupByNodeName
* Test NodeFit() case where pods matches inter-pod anti-affinity
* Test for inter-pod anti-affinity pods  match terms, have label selector

* NodeFit inter-pod anti-affinity check returns early if affinity spec not set

test/run-e2e-tests.sh

@@ -20,6 +20,7 @@ set -o nounset
 
 # Set to empty if unbound/empty
 SKIP_INSTALL=${SKIP_INSTALL:-}
+KIND_E2E=${KIND_E2E:-}
 
 # This just runs e2e tests.
 if [ -n "$KIND_E2E" ]; then