Update to clap v3

Cargo.toml

@@ -1,15 +1,14 @@
 [package]
 authors = ["chevdor <chevdor@gmail.com>"]
+description = "A command line utility written in Rust to render templates from json|toml|yaml && ENV, using the tera templating engine"
 edition = "2021"
+license = "MIT"
 name = "teracli"
-version = "0.2.1"
-description = "A command line utility written in Rust to render templates from json|toml|yaml && ENV, using the tera templating engine"
 readme = "README.md"
-license = "MIT"
+version = "0.2.1"
 
 [dependencies]
-clap = "=3.0.0-beta.4"
-clap_derive = "=3.0.0-beta.4"
+clap = {version = "3.0", features = ["derive", "env", "unicode", "cargo"]}
 env_logger = "0.9"
 log = "0.4"
 serde = "1.0"

src/main.rs

@@ -3,7 +3,7 @@ mod template;
 mod wrapped_context;
 
 use crate::template::Template;
-use clap::{crate_name, crate_version, Clap};
+use clap::{crate_name, crate_version, StructOpt};
 use env_logger::Env;
 use log::{debug, info, trace};
 use opts::*;

src/opts.rs

@@ -1,11 +1,10 @@
-use clap::{crate_authors, crate_version, AppSettings, Clap};
+use clap::{crate_authors, crate_version, Parser};
 use std::path::PathBuf;
 
 /// Command line utility for the tera templating engine. You need to provide a template using the tera syntax
 /// as well as some data (various format are supported).
-#[derive(Clap, Debug)]
+#[derive(Debug, Parser)]
 #[clap(version = crate_version!(), author = crate_authors!())]
-#[clap(setting = AppSettings::ColoredHelp)]
 pub struct Opts {
 	/// Location of the template.
 	#[clap(short, long)]