Use reqwest instead of ureq for download

[nickfarrow]

Attempt at resolving MSRV issues caused by ureq: #95

I believe this reqwest version 0.10 has MSRV 1.39.0

[RCasatta]

Thanks for the PR.
I opened another one #99 based on yours because I want to target the 0.27.* branch to support MSRV 1.41.1

Unfortunately it doesn't look that reqwest 0.10.x has MSRV 1.39:

$ cargo +1.41.1 check
error: failed to download `indexmap v1.9.1`

Caused by:
  unable to get packages from source

Caused by:
  failed to parse manifest at `/home/casatta/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/indexmap-1.9.1/Cargo.toml`

Caused by:
  failed to parse the `edition` key

Caused by:
  supported edition values are `2015` or `2018`, but `2021` is unknown

$ cargo tree -i indexmap
indexmap v1.9.1
└── h2 v0.2.7
    └── hyper v0.13.10
        ├── hyper-tls v0.4.3
        │   └── reqwest v0.10.10
        │       [build-dependencies]
        │       └── bitcoind v0.27.1 (/home/casatta/git/bitcoind)
        └── reqwest v0.10.10 (*)

[nickfarrow]

Ahh damn... Do you know why the reqwest CI says 1.39? I guess i'm going to have to look for another crate... running out of options

[RCasatta]

I didn't investigate the reasons, but I supposed semver of dependencies now select newer deps than the one selected when that CI was run

[RCasatta]

I think #102 is approximately solving the MSRV issues