Auto merge of #5912 - rust-lang:dependabot/cargo/opener-0.3.0, r=alexcrichton

Update opener requirement from 0.2.0 to 0.3.0

Updates the requirements on [opener](https://github.com/Seeker14491/opener) to permit the latest version.
<details>
<summary>Changelog</summary>

*Sourced from [opener's changelog](https://github.com/Seeker14491/opener/blob/master/CHANGELOG.md).*

> ## [0.3.0] - 2018-08-18
> ### Added
> - `stderr` field to `OpenError::ExitStatus` variant, which captures anything the failed process wrote to stderr.
>
> ## [0.2.0] - 2018-08-08
> ### Removed
> - The `open_sys` function, which was erroneously pub on non-Windows builds.
>
> ## [0.1.0] - 2018-08-08
> - Initial release.
</details>
<details>
<summary>Commits</summary>

- See full diff in [compare view](https://github.com/Seeker14491/opener/commits/v0.3.0)
</details>
<br />

Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting `@dependabot rebase`.

---

<details>
<summary>Dependabot commands and options</summary>
<br />

You can trigger Dependabot actions by commenting on this PR:
- `@dependabot rebase` will rebase this PR
- `@dependabot merge` will merge this PR after your CI passes on it
- `@dependabot reopen` will reopen this PR if it is closed
- `@dependabot ignore this [patch|minor|major] version` will close this PR and stop Dependabot creating any more for this minor/major version (unless you reopen the PR or upgrade to it yourself)
- `@dependabot ignore this dependency` will close this PR and stop Dependabot creating any more for this dependency (unless you reopen the PR or upgrade to it yourself)
- `@dependabot use these labels` will set the current labels as the default for future PRs for this repo and language
- `@dependabot use these reviewers` will set the current reviewers as the default for future PRs for this repo and language
- `@dependabot use these assignees` will set the current assignees as the default for future PRs for this repo and language
- `@dependabot use this milestone` will set the current milestone as the default for future PRs for this repo and language
- `@dependabot badge me` will comment on this PR with code to add a "Dependabot enabled" badge to your readme

Additionally, you can set the following in your Dependabot [dashboard](https://app.dependabot.com):
- Update frequency (including time of day and day of week)
- Automerge options (never/patch/minor, and dev/runtime dependencies)
- Pull request limits (per update run and/or open at any time)
- Out-of-range updates (receive only lockfile updates, if desired)
- Security updates (receive only security updates, if desired)

Finally, you can contact us by mentioning @dependabot.

</details>

Author: bors

Cargo.toml

@@ -40,7 +40,7 @@ libc = "0.2"
 log = "0.4"
 libgit2-sys = "0.7.5"
 num_cpus = "1.0"
-opener = "0.2.0"
+opener = "0.3.0"
 rustfix = "0.4.2"
 same-file = "1"
 semver = { version = "0.9.0", features = ["serde"] }