Add feature isahc-static-ssl

With isahc-static-curl feature compiling a static build was still not
achievable since it still needed system-wide installed OpenSSL
libraries. With the isahc-static-ssl feature was added, now its
possible to compile the library without OpenSSL libraries installed.

The src/task_info.rs file had a failing doc test due not using
environmental variables like other tests do. This issue was fixed.

Author: TcOhamtyw6lt

Cargo.toml

@@ -40,6 +40,7 @@ wasm-bindgen-futures = "0.4"
 [features]
 default = ["isahc-static-curl"]
 isahc-static-curl = ["isahc/static-curl"]
+isahc-static-ssl = ["isahc/static-ssl"]
 
 [dev-dependencies]
 env_logger = "0.10"

src/task_info.rs

@@ -50,9 +50,11 @@ impl TaskInfo {
     /// #    kind: String,
     /// # }
     /// #
+    /// # let MEILISEARCH_URL = option_env!("MEILISEARCH_URL").unwrap_or("http://localhost:7700");
+    /// # let MEILISEARCH_API_KEY = option_env!("MEILISEARCH_API_KEY").unwrap_or("masterKey");
     /// #
     /// # futures::executor::block_on(async move {
-    /// # let client = Client::new("http://localhost:7700", Some("masterKey"));
+    /// # let client = Client::new(MEILISEARCH_URL, Some(MEILISEARCH_API_KEY));
     /// let movies = client.index("movies_wait_for_completion");
     ///
     /// let status = movies.add_documents(&[