build(deps): update tonic requirement from 0.2 to 0.4

[dependabot-preview]

Updates the requirements on tonic to permit the latest version.

Changelog

Sourced from tonic's changelog.

0.4.0 (2021-01-15)

This version brings Tonic inline with Tokio 1.0 and Prost 0.7! This release also includes new versions of tonic-types, tonic-build, and tonic-health.

Bug Fixes

• transport: return Poll::ready until error is consumed (#536) (dafea9a)
• gracefully handle bad native certs (#520) (fe4d5b9), closes #519
• build: Add content-type for generated unimplemented service (#441) (62c1230)
• build: Match namespace code with other generated packages (#472) (1b03ece)
• transport: Add content-type for Unimplemented (#434) (594a542)
• transport: reconnect lazy connections after first failure (#458) (e9910d1), closes #452
• client: Merge trailer and initla headers into status on err (#510)
• transport: Fix TLS accept w/ peer certs (#535) (41c51f1)

Features

• status: implement Fromio::Error for Status (#500) (fc86563)
• transport: Add Router::into_service (#419) (37f6733)
• transport: add max http2 frame size to server. (#529) (31936e0), closes #264
• transport: add user-agent header to client requests. (#457) (d4899df), closes #453
• transport: Connect lazily in the load balanced channel (#493) (2e964c7)
• transport: expose HTTP2 server keepalive interval and timeout (#486) (2b9cdb9), closes #474
• transport: Move error! to debug! (#537) (a7778ad)
• transport: Do not panic when building and Endpoint with an invali… (#438) (26ce9d1), closes #438

BREAKING CHANGES

• TryFrom API has been changed.
• Upgraded to tokio 1.0 and prost 0.7.
• Channel now implements Service instead of GrpcService.

0.3.1 (2020-08-20)

Bug Fixes

• transport: Return connection error on Channel::connect (#413) (2ea17b2), closes #403

0.3.0 (2020-07-13)

Bug Fixes

• Status::details leaking base64 encoding (#395) (2c4c544), closes #379
• build: Allow empty packages (#382) (f085aba), closes #381

... (truncated)

Commits

• e511f17 Fix tonic-health cargo path issues
• fda2d68 chore: Prepare 0.4 release (#538)
• a7778ad feat(transport): Move error! to debug! (#537)
• dafea9a fix(transport): return Poll::ready until error is consumed (#536)
• 31936e0 feat(transport): add max http2 frame size to server. (#529)
• 41c51f1 feat(transport): Fix TLS accept w/ peer certs (#535)
• 4974604 ci: Disable deny workflow (#534)
• fdda5ae Upgrade to Tokio 1.0.0 ecosystem (#530)
• fe4d5b9 fix: gracefully handle bad native certs (#520)
• a6be836 Add h2 error conversion for Status (#509)
• Additional commits viewable in compare view

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[dependabot-preview]

Superseded by #348.