e2e: accept context from Ginkgo

Every ginkgo callback should return immediately when a timeout occurs or the
test run manually gets aborted with CTRL-C. To do that, they must take a ctx
parameter and pass it through to all code which might block.

This is a first automated step towards that: the additional parameter got added
with

    sed -i 's/\(framework.ConformanceIt\|ginkgo.It\)\(.*\)func() {$/\1\2func(ctx context.Context) {/' \
        $(git grep -l -e framework.ConformanceIt -e ginkgo.It )
    $GOPATH/bin/goimports -w $(git status | grep modified: | sed -e 's/.* //')

log_test.go was left unchanged.

hack/conformance/check_conformance_test_requirements.go

@@ -30,7 +30,7 @@ import (
 )
 
 const (
-	//e.g. framework.ConformanceIt("should provide secure master service ", func() {
+	//e.g. framework.ConformanceIt("should provide secure master service ", func(ctx context.Context) {
 	patternStartConformance = `framework.ConformanceIt\(.*, func\(\) {$`
 	patternEndConformance   = `}\)$`
 	patternSkip             = `e2eskipper.Skip.*\(`