Does not build

This repository does not build. The build ends with the error message:

```
 ---> Running in 75921ae12df8
[91m/bin/sh: 1: /home/main/anaconda/envs/python3/bin/pip: not found[0m
could not build image binder-project-example-dockerfile-two: Error: build failed for imageName: binder-project-example-dockerfile-two
registering template for binder-project-example-dockerfile-two
```
