quoting of environ is wrong

[chipaca]

If I have an environment value that has double quotes,

environment:
  foo: 'some "quoted value"'

then spread will (incorrectly) do

export foo="some "quoted value""

which sets foo to "some quoted" and exports foo and value. This is not what was intended.

What should happen is that spread properly quotes the value. One easy way to do this would be to use %q, possibly. I haven't tested this.

Note this also means that all env vars need doubling of backslashes, needlessly.