Update README with platform support

After the Travis migration, the apparent support status
has changed. This might be just a few test issues?
Nonetheless, be honest and don't guess:
Remove arches unlikely to be supported outright,
and update with the latest CI results.

The old badges also can go.

Cargo.toml

@@ -18,9 +18,6 @@ rustdoc-args = ["--cfg", "doc_cfg"]
 # RUSTDOCFLAGS="--cfg doc_cfg" cargo +nightly doc --features into_bits --no-deps --open
 
 [badges]
-appveyor = { repository = "rust-lang/packed_simd" }
-travis-ci = { repository = "rust-lang/packed_simd" }
-codecov = { repository = "rust-lang/packed_simd" }
 is-it-maintained-issue-resolution = { repository = "rust-lang/packed_simd" }
 is-it-maintained-open-issues = { repository = "rust-lang/packed_simd" }
 maintenance = { status = "experimental" }

README.md

@@ -2,10 +2,10 @@
 
 ## Implementation of [Rust RFC #2366: `std::simd`][rfc2366]
 
-[![Travis-CI Status]][travis] <!-- [![Appveyor Status]][appveyor] --> [![Latest Version]][crates.io] [![docs]][master_docs]
+[![Latest Version]][crates.io] [![docs]][master_docs]
 
 **WARNING**: this crate only supports the most recent nightly Rust toolchain
-and will be superseded by [stdsimd](https://github.com/rust-lang/stdsimd).
+and will be superseded by [`#![feature(portable_simd)]`](https://github.com/rust-lang/portable-simd).
 
 ## Documentation
 
@@ -71,30 +71,25 @@ whether the test suite passes for a given target.
 | `i586-unknown-linux-gnu` | ✓ | ✗ |
 | `i686-unknown-linux-gnu` | ✓ | ✗ |
 | `x86_64-unknown-linux-gnu` | ✓ | ✓ |
-| `arm-unknown-linux-gnueabi` | ✗ | ✗ |
 | `arm-unknown-linux-gnueabihf` | ✓ | ✓ |
 | `armv7-unknown-linux-gnueabi` | ✓ | ✓ |
 | `aarch64-unknown-linux-gnu` | ✓ | ✓ |
-| `mips-unknown-linux-gnu` | ✓ | ✗ |
-| `mipsel-unknown-linux-musl` | ✓ | ✗ |
-| `mips64-unknown-linux-gnuabi64` | ✓ | ✗ |
-| `mips64el-unknown-linux-gnuabi64` | ✓ | ✗ |
-| `powerpc-unknown-linux-gnu` | ✗ | ✗ |
-| `powerpc64-unknown-linux-gnu` | ✗ | ✗ |
+| `powerpc-unknown-linux-gnu` | ✓ | ✗ |
+| `powerpc64-unknown-linux-gnu` | ✓ | ✗ |
 | `powerpc64le-unknown-linux-gnu` | ✓ | ✓ |
-| `s390x-unknown-linux-gnu` | ✗ | ✗ |
+| `s390x-unknown-linux-gnu` | ✓ | ✗ |
 | `sparc64-unknown-linux-gnu` | ✓ | ✗ |
 | `thumbv7neon-unknown-linux-gnueabihf` | ✓ | ✓ |
 | **MacOSX** | **build** | **run** |
 | `x86_64-apple-darwin` | ✓ | ✓ |
 | **Android** | **build** | **run** |
 | `x86_64-linux-android` | ✓ | ✓ |
-| `arm-linux-androideabi`  | ✓ | ✓ |
-| `aarch64-linux-android` | ✓ | ✓ |
-| `thumbv7neon-linux-androideabi` | ✗ | ✗ |
+| `armv7-linux-androideabi` | ✓ | ✗ |
+| `aarch64-linux-android` | ✓ | ✗ |
+| `thumbv7neon-linux-androideabi` | ✓ | ✗ |
 | **iOS** | **build** | **run** |
-| `x86_64-apple-ios` | ✓ | ✗ |
-| `aarch64-apple-ios` | ✓ | ✗ |
+| `x86_64-apple-ios` | ✗ | ✗ |
+| `aarch64-apple-ios` | ✗ | ✗ |
 
 
 ## Machine code verification