When a job has two or more dependencies, it isn't downloading at specified order
### Summary
When a job has two or more dependencies, it isn't downloading at specified order.
### Steps to reproduce
<details>
<summary>Expand for `.gitlab-ci.yml` sample code</summary>
<pre>
```yml
stages:
- build
- pack
build-server:
stage: build
script:
- yarn install
- yarn server:build
artifacts:
paths:
- "$CI_PROJECT_DIR/artifacts/"
build-client:
stage: build
script:
- yarn install
- yarn client:build
artifacts:
paths:
- "$CI_PROJECT_DIR/artifacts/"
pack-app:
stage: pack
dependencies:
- build-server
- build-client
script:
- yarn install
- yarn docker:image:build
- yarn docker:image:publish
```
</pre>
</details>
**Aditional Information**: Always `build-server` is finished before `build-client`.
### What is the current *bug* behavior?
During the `pack-app` job output, it's downloading first the artifacts from `build-client`.
```bash
Downloading artifacts for build-client (161831)...
Downloading artifacts from coordinator... ok id=161831 responseStatus=200 OK token=hgqy37n1
Downloading artifacts for build-server (161832)...
Downloading artifacts from coordinator... ok id=161832 responseStatus=200 OK token=qibAXas4
```
### What is the expected *correct* behavior?
The artifacts must be downloaded at same order specified at `dependencies` configuration of te job.
```bash
Downloading artifacts for build-server (161832)...
Downloading artifacts from coordinator... ok id=161832 responseStatus=200 OK token=qibAXas4
Downloading artifacts for build-client (161831)...
Downloading artifacts from coordinator... ok id=161831 responseStatus=200 OK token=hgqy37n1
```
### Output of checks
This bug happens on GitLab EE on premisse, version 11.7.5-ee
issue