Bug: `deno task` erroring on brace expansion

[marvinhagemeister]

Steps to reproduce

1. Clone https://github.com/sass/node-sass
2. Run npm i
3. Run DENO_FUTURE=1 deno task test

Error:

$ DENO_FUTURE=1 deno task test
Task test mocha test/{*,**/**}.js
error: Error parsing script 'test'.

Caused by:
    Unexpected character.
      {*,**/**}.js

Version: Deno 1.44.4

[dsherret]

Related issue: https://github.com/denoland/deno_task_shell/issues/91

deno task doesn't support brace expansion at the moment.

[uncenter]

Globs lacking brace expansion support also affects include and exclude for deno.json I think. Might be worth documenting this for now, deno appears to run fine (no configuration errors/warnings) but not understand the pattern.