General Cargo.toml cleanup. (#529)

* General Cargo.toml cleanup.

 - Remove travis-ci attributes.
 - Remove "experimental" badges from actively-developed crates.
 - Reflow some long lines.
 - Use dependency features consistently.
 - Add readme attributes

* Update WASI to the latest trunk.

This notably adds a .gitignore file for the WASI directory.

crates/misc/py/Cargo.toml

@@ -6,6 +6,8 @@ description = "Python extension for Wasmtime"
 license = "Apache-2.0 WITH LLVM-exception"
 categories = ["wasm", "python"]
 keywords = ["webassembly", "wasm"]
+repository = "https://github.com/CraneStation/wasmtime"
+readme = "README.md"
 edition = "2018"
 
 [lib]
@@ -13,11 +15,11 @@ name = "_wasmtime"
 crate-type = ["cdylib"]
 
 [dependencies]
-cranelift-codegen = { version = "0.49" }
-cranelift-native = { version = "0.49" }
-cranelift-entity = { version = "0.49" }
-cranelift-wasm = { version = "0.49" }
-cranelift-frontend = { version = "0.49" }
+cranelift-codegen = "0.49"
+cranelift-native = "0.49"
+cranelift-entity = "0.49"
+cranelift-wasm = "0.49"
+cranelift-frontend = "0.49"
 wasmtime-environ = { path = "../../environ" }
 wasmtime-interface-types = { path = "../../interface-types" }
 wasmtime-jit = { path = "../../jit" }
@@ -26,7 +28,7 @@ target-lexicon = { version = "0.9.0", default-features = false }
 anyhow = "1.0.19"
 region = "2.0.0"
 wasmparser = "0.39.2"
+pyo3 = { version = "0.8.0", features = ["extension-module"] }
 
-[dependencies.pyo3]
-version = "0.8.0"
-features = ["extension-module"]
+[badges]
+maintenance = { status = "actively-developed" }