[rc] [dev] Dev Server Feature Branch

[EverlastingBugstopper]

Fixes #845

Wrangler Dev Server -- Feature Branch

Testing Instructions - these should be included in the rc when it gets cut

---

Testing

Your local rustc -V must be at least 1.39.0. You can update by running rustup update stable.

You can install this branch by running cargo install --git https://github.com/cloudflare/wrangler --branch avery/a-time-sync --debug --force

(eventually that will get merged and you can install from this branch)

Go to a worker directory and run wrangler dev and curl/postman away!

$ wrangler dev --help
wrangler-dev 
👂  Start a local server for developing your worker

USAGE:
    wrangler dev [OPTIONS]

FLAGS:
        --help    Prints help information

OPTIONS:
    -h, --host <host>    domain to test behind your worker. defaults to example.com
    -i, --ip <ip>        ip to listsen on. defaults to localhost
    -p, --port <port>    port to listen on. defaults to 8787

[steveklabnik]

i think this looks good overall! I have a few style pointers, some of which are purely personal preference, and i'm not familiar with all of wrangler, so maybe consistency is better. please pick and choose whichever of these you want to take advice from :)

[EverlastingBugstopper]

thanks for the review @steveklabnik - super super helpful :)

generally we do not have a style in wrangler and i would not describe it as consistent - very happy to follow these style suggestions

[ashleymichal]

🆗