I think this syntax is called "block literal".  It's handy for multi-line stuff but I switched everything to it because it unambiguously represents a string.  For example, if I wanted one of these to be `true` then I could write:

```
  - "true"
```

or

```
  - |
    true
```

but if I write

```
  - true
```

then I have failed to express the desired intent.

This became important for an intermediate version of the config not represented by this diff where the install step changed from:

```
  - pip install "$(eval ${ELIOT})"
```

to

```
  - [ -v ELIOT ] && pip install "$(eval ${ELIOT})"
```

The former worked because whatever the magic rules for deciding something is a string are they kicked in for that version.  The latter failed because apparently those magic rules reject things that start with `[`.

Switching to a syntax with fewer magic rules seemed like a good simplification.  I could have switched the single line steps to use quotes but I'd rather minimize the different kinds of syntax being used.