Bring tide to root, and allow cargo run --example

[yoshuawuyts]

Description

Moves the tide submodule to the root of the crate, allows running examples using:

$ cargo run --example <example>

Also makes the examples to be run standalone without a need for lib.rs. Ref #223.

Motivation and Context

This patch is an alternative to #227. As explained in #223 (comment), I think it's preferable if we keep Cargo's default behavior of being able to run examples using cargo run --example.

I spent some time today trying to figure out how to run our examples, only to find out that they weren't runnable, which was unexpected, and admittedly rather frustrating.

How Has This Been Tested?

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[prasannavl]

Awesome! I do think this is much nicer, and also keeps things consistent with runtime. My initial motivation to not go this route, was that we may have to tweak tooling scaffolds and other experience if porting over from futures, tokio, etc.

But yeah, we can take the new path and figure things out as we go :)

[fairingrey]

This approach is neat, reminds me of the way actix-web is laid out (with the main crate at root, so we no longer rely on a workspace manifest alone). I like it 👍

PS: Thanks for fixing my example!

[prasannavl]

If the travis bit can be fixed, I think we can merge this and handle the example clippy warnings post merge, for this particular instance.

[fairingrey]

@prasannavl Yup, after these Travis runs finish, clippy should only be yelling at the examples (and we can just get those fixed up in a later PR)

[fairingrey]

Clippy freaks out on the examples, but as mentioned before we can fix it later -- merging!