Add e2e tests to verify plugin functionality

[chetan-rns]

• Add e2e tests using Ginkgo to verify the functionality of the Route plugin.
• Add reusable fixtures
• Add a script that will configure the plugin and run e2e tests
• Update the go.mod to accommodate the OpenShift and the Rollouts package

Testing:

1. Login to an OCP cluster.
2. Make sure you have the argo-rollouts repository locally.
3. Run the e2e test inside the rollouts-plugin-trafficrouter-openshift repository

$ ./hack/run-e2e-local.sh <ARGO_ROLLOUTS_PATH>

Fixes: #5

[chetan-rns]

@jgwest I've disabled the VCS stamping to fix the gosec error. Let me know if this workaround is okay. I suspect it has something to do with how git is configured when running gosec inside a container.

 GOFLAGS: -buildvcs=false

[jgwest]

LGTM, thanks @chetan-rns!