Bump to version 0.3.0 (#186)

* Bump to version 0.3.0

Signed-off-by: Xuanwo <github@xuanwo.io>

* Update docs

Signed-off-by: Xuanwo <github@xuanwo.io>
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 061cdda..f606d68 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,22 @@
 The format is based on [Keep a Changelog](https://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](https://semver.org/).
 
+## [v0.3.0] - 2022-03-25
+
+### Added
+
+- feat: Add azure blob support (#165)
+- feat: Add tracing support via minitrace (#175)
+- feat(service/s3): Implement server side encryption support (#182)
+
+### Changed
+
+- chore: Level down some log entry to debug (#181)
+
+### Fixed
+
+- fix(service/s3): Endpoint template should be applied if region exists (#180)
+
 ## [v0.2.5] - 2022-03-22
 
 ### Added
@@ -181,6 +197,7 @@
 
 Hello, OpenDAL!
 
+[v0.3.0]: https://github.com/datafuselabs/opendal/compare/v0.2.5...v0.3.0
 [v0.2.5]: https://github.com/datafuselabs/opendal/compare/v0.2.4...v0.2.5
 [v0.2.4]: https://github.com/datafuselabs/opendal/compare/v0.2.3...v0.2.4
 [v0.2.3]: https://github.com/datafuselabs/opendal/compare/v0.2.2...v0.2.3
diff --git a/Cargo.toml b/Cargo.toml
index 497609a..9377976 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -7,7 +7,7 @@
 license = "Apache-2.0"
 name = "opendal"
 repository = "https://github.com/datafuselabs/opendal"
-version = "0.2.5"
+version = "0.3.0"
 
 [workspace]
 members = ["opendal_test"]
@@ -23,6 +23,7 @@
 anyhow = "1"
 async-compat = "0.2"
 async-trait = "0.1"
+base64 = "0.13.0"
 bstr = "0.2"
 bytes = "1"
 futures = { version = "0.3", features = ["alloc"] }
@@ -30,6 +31,7 @@
 hyper = { version = "0.14", features = ["full"] }
 hyper-tls = "0.5.0"
 log = "0.4"
+md5 = "0.7.0"
 metrics = "0.18"
 minitrace = "0.4.0"
 once_cell = "1"
@@ -43,8 +45,6 @@
 time = "0.3.7"
 tokio = { version = "1.17", features = ["full"] }
 tower = "0.4"
-base64="0.13.0"
-md5 = "0.7.0"
 
 [dev-dependencies]
 anyhow = "1.0"
diff --git a/src/lib.rs b/src/lib.rs
index a9c0c08..1aedd95 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -64,6 +64,12 @@
 //!     Ok(())
 //! }
 //! ```
+//!
+//! ## Supported Services
+//!
+//! - [fs][crate::services::fs]: POSIX alike file system.
+//! - [memory][crate::services::memory]: In memory backend support.
+//! - [s3][crate::services::s3]: AWS services like S3.
 extern crate core;
 
 mod accessor;
diff --git a/src/scheme.rs b/src/scheme.rs
index 88620ea..d2d350c 100644
--- a/src/scheme.rs
+++ b/src/scheme.rs
@@ -24,6 +24,7 @@
     // TODO: Although we don't have azblob support for now, but we need to add it for compatibility. We will implement azblob support as soon as possible.
     Azblob,
     Fs,
+    Memory,
     S3,
 }
 
@@ -35,6 +36,7 @@
         match s.as_str() {
             "azblob" => Ok(Scheme::Azblob),
             "fs" => Ok(Scheme::Fs),
+            "memory" => Ok(Scheme::Memory),
             "s3" => Ok(Scheme::S3),
 
             // TODO: it's used for compatibility with dal1, should be removed in the future