Merge #509

509: Bump tokio from 1.5.0 to 1.6.0 r=thomaseizinger a=dependabot[bot]

Bumps [tokio](https://github.com/tokio-rs/tokio) from 1.5.0 to 1.6.0.
<details>
<summary>Release notes</summary>
<p><em>Sourced from <a href="https://github.com/tokio-rs/tokio/releases">tokio's releases</a>.</em></p>
<blockquote>
<h2>Tokio v1.6.0</h2>
<h1>1.6.0 (May 14, 2021)</h1>
<h3>Added</h3>
<ul>
<li>fs: try doing a non-blocking read before punting to the threadpool (<a href="https://github-redirect.dependabot.com/tokio-rs/tokio/issues/3518">#3518</a>)</li>
<li>io: add <code>write_all_buf</code> to <code>AsyncWriteExt</code> (<a href="https://github-redirect.dependabot.com/tokio-rs/tokio/issues/3737">#3737</a>)</li>
<li>io: implement <code>AsyncSeek</code> for <code>BufReader</code>, <code>BufWriter</code>, and <code>BufStream</code> (<a href="https://github-redirect.dependabot.com/tokio-rs/tokio/issues/3491">#3491</a>)</li>
<li>net: support non-blocking vectored I/O (<a href="https://github-redirect.dependabot.com/tokio-rs/tokio/issues/3761">#3761</a>)</li>
<li>sync: add <code>mpsc::Sender::{reserve_owned, try_reserve_owned}</code> (<a href="https://github-redirect.dependabot.com/tokio-rs/tokio/issues/3704">#3704</a>)</li>
<li>sync: add a <code>MutexGuard::map</code> method that returns a <code>MappedMutexGuard</code> (<a href="https://github-redirect.dependabot.com/tokio-rs/tokio/issues/2472">#2472</a>)</li>
<li>time: add getter for Interval's period (<a href="https://github-redirect.dependabot.com/tokio-rs/tokio/issues/3705">#3705</a>)</li>
</ul>
<h3>Fixed</h3>
<ul>
<li>io: wake pending writers on <code>DuplexStream</code> close (<a href="https://github-redirect.dependabot.com/tokio-rs/tokio/issues/3756">#3756</a>)</li>
<li>process: avoid redundant effort to reap orphan processes (<a href="https://github-redirect.dependabot.com/tokio-rs/tokio/issues/3743">#3743</a>)</li>
<li>signal: use <code>std::os::raw::c_int</code> instead of <code>libc::c_int</code> on public API (<a href="https://github-redirect.dependabot.com/tokio-rs/tokio/issues/3774">#3774</a>)</li>
<li>sync: preserve permit state in <code>notify_waiters</code> (<a href="https://github-redirect.dependabot.com/tokio-rs/tokio/issues/3660">#3660</a>)</li>
<li>task: update <code>JoinHandle</code> panic message (<a href="https://github-redirect.dependabot.com/tokio-rs/tokio/issues/3727">#3727</a>)</li>
<li>time: prevent <code>time::advance</code> from going too far (<a href="https://github-redirect.dependabot.com/tokio-rs/tokio/issues/3712">#3712</a>)</li>
</ul>
<h3>Documented</h3>
<ul>
<li>net: hide <code>net::unix::datagram</code> module from docs (<a href="https://github-redirect.dependabot.com/tokio-rs/tokio/issues/3775">#3775</a>)</li>
<li>process: updated example (<a href="https://github-redirect.dependabot.com/tokio-rs/tokio/issues/3748">#3748</a>)</li>
<li>sync: <code>Barrier</code> doc should use task, not thread (<a href="https://github-redirect.dependabot.com/tokio-rs/tokio/issues/3780">#3780</a>)</li>
<li>task: update documentation on <code>block_in_place</code> (<a href="https://github-redirect.dependabot.com/tokio-rs/tokio/issues/3753">#3753</a>)</li>
</ul>
</blockquote>
</details>
<details>
<summary>Commits</summary>
<ul>
<li><a href="580dc9594c"><code>580dc95</code></a> chore: prepare Tokio v1.6.0 (<a href="https://github-redirect.dependabot.com/tokio-rs/tokio/issues/3782">#3782</a>)</li>
<li><a href="8c395dfe61"><code>8c395df</code></a> io: impl AsyncSeek for BufReader/BufWriter/BufStream (<a href="https://github-redirect.dependabot.com/tokio-rs/tokio/issues/3491">#3491</a>)</li>
<li><a href="e188e99ca3"><code>e188e99</code></a> process: avoid redundant effort to reap orphan processes (<a href="https://github-redirect.dependabot.com/tokio-rs/tokio/issues/3743">#3743</a>)</li>
<li><a href="0b93bd511d"><code>0b93bd5</code></a> net: support non-blocking vectored I/O (<a href="https://github-redirect.dependabot.com/tokio-rs/tokio/issues/3761">#3761</a>)</li>
<li><a href="d846bf24b1"><code>d846bf2</code></a> sync: Barrier doc should use task, not thread (<a href="https://github-redirect.dependabot.com/tokio-rs/tokio/issues/3780">#3780</a>)</li>
<li><a href="9ff7d8c352"><code>9ff7d8c</code></a> net: hide net::unix::datagram module from docs (<a href="https://github-redirect.dependabot.com/tokio-rs/tokio/issues/3775">#3775</a>)</li>
<li><a href="8324317005"><code>8324317</code></a> doc: fix doc-cfg on io::duplex, io::copy_bidirectional, and task::unconstrain...</li>
<li><a href="7207e3ca43"><code>7207e3c</code></a> signal: use std::os::raw::c_int instead of libc::c_int on public API (<a href="https://github-redirect.dependabot.com/tokio-rs/tokio/issues/3774">#3774</a>)</li>
<li><a href="312321cbd3"><code>312321c</code></a> chore: enable syntax highlighting for toml in readme</li>
<li><a href="17c7ce616c"><code>17c7ce6</code></a> benches: fix build error (<a href="https://github-redirect.dependabot.com/tokio-rs/tokio/issues/3769">#3769</a>)</li>
<li>Additional commits viewable in <a href="https://github.com/tokio-rs/tokio/compare/tokio-1.5.0...tokio-1.6.0">compare view</a></li>
</ul>
</details>
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Cargo.lock

@@ -4093,9 +4093,9 @@ checksum = "cda74da7e1a664f795bb1f8a87ec406fb89a02522cf6e50620d016add6dbbf5c"
 
 [[package]]
 name = "tokio"
-version = "1.5.0"
+version = "1.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "83f0c8e7c0addab50b663055baf787d0af7f413a46e6e7fb9559a4e4db7137a5"
+checksum = "bd3076b5c8cc18138b8f8814895c11eb4de37114a5d127bafdc5e55798ceef37"
 dependencies = [
  "autocfg 1.0.1",
  "bytes 1.0.1",