`make test` fails

**Describe the bug**
In my work on #42, I'm unable to successfully run the test suite, even on `master`. I've tried kind 0.9.0, [as well as 0.8.1, which @willholley has reported successfully works for him](https://github.com/apache/couchdb-helm/pull/42#issuecomment-696183021).

**Version of Helm and Kubernetes**:

- Debian 10.5
- `docker-ce` version 18.06.3~ce
- kind v0.8.1 go1.15 linux/amd64

**What happened**:

```
$ make test
./test/e2e-kind.sh
Running ct container...
9e16a8d8640fdfa36003c17e4ca5d16a9fb13818eda235ad6fc29bb9a2ddc4ae

Deleting cluster "chart-testing" ...
Creating cluster "chart-testing" ...
✓ Ensuring node image (kindest/node:v1.18.2) 🖼
✓ Preparing nodes 📦 📦
✓ Writing configuration 📜
✓ Starting control-plane 🕹️
✓ Installing CNI 🔌
✓ Installing StorageClass 💾
✓ Joining worker nodes 🚜
✓ Waiting ≤ 1m0s for control-plane = Ready ⏳
• Ready after 0s 💚
Set kubectl context to "kind-chart-testing"
You can now use your cluster with:

kubectl cluster-info --context kind-chart-testing

Thanks for using kind! 😊
Copying kubeconfig to container...
error: Missing or incomplete configuration info. Please point to an existing, complete config file:

1. Via the command-line flag --kubeconfig
2. Via the KUBECONFIG environment variable
3. In your home directory as ~/.kube/config

To view or setup config directly use the 'config' command.
Removing ct container...
Deleting cluster "chart-testing" ...
Done!
make: *** [Makefile:31: test] Error 1
```

**What you expected to happen**:

Tests pass.

**How to reproduce it** (as minimally and precisely as possible):

1. Install kind (`GO111MODULE="on" go get sigs.k8s.io/kind@v0.8.1 && kind create cluster`)
2. Run `make test`

**Anything else we need to know**:

I expect this is related to my local kubernetes config not matching what the tests expect. It probably just needs a small update to the README mentioning whatever the missing requirement is.

Start with the `test` target in Makefile and test/e2e-kind.sh, then reproduce the reported `make test` failure using the listed kind and Kubernetes setup. Trace the kubeconfig copy step and check the README for the expected local configuration; done means the documented setup allows the test command to complete successfully.

Written by the indexing model from the issue text.