Add basic e2e test to ensure that the example works

[camilamacedo86]

Now we will not generate the project/testdata. But it can be improved after with the plugin implementation and will be helpful to ensure the changes in the repo. Such as: https://github.com/operator-framework/operator-sdk/tree/master/test/e2e-new

[joelanford]

An e2e test has added in the plugin branch that runs pretty much the same e2e test that we run in the SDK helm-operator e2e. See joelanford@a21990f