Add SetVal trait, module info hook, and remove unused codes.

Author: jmjoy

Cargo.toml

@@ -9,6 +9,5 @@ members = [
 
     # internal
     "examples/hello",
-#    "examples/hello-class",
 #    "examples/mini-curl",
 ]

README.md

@@ -2,31 +2,16 @@
 
 A library that allows us to write PHP extensions using pure Rust and using safe Rust whenever possible.
 
-***Now the project is still under development.***
-
 ## Requirement
 
-- php version: 
-- libclang >= 9
+- os: linux
+- libclang: version >= 9
+- php: version in (7.1, 7.2, 7.3, 7.4, 8.0), mode: nts
 
 ## Usage
 
 Now see [examples](examples).
 
-<!--
-First you have to install `cargo-generate`:
-
-# ```bash
-cargo install cargo-generate
-```
-
-Then create a PHP extension project from the [template](https://github.com/jmjoy/phper-ext-skel.git):
-
-```bash
-cargo generate --git https://github.com/jmjoy/phper-ext-skel.git
-```
--->
-
 ## License
 
 [Unlicense](LICENSE).