message: Improve `check_contract` description
diff: @@ -7,9 +7,9 @@ use cosmwasm_vm::features_from_csv;
  use cosmwasm_vm::internals::{check_wasm, compile};
  pub fn main() {
  - let matches = App::new("Module compilation")
  + let matches = App::new("Contract checking")
  .version("0.1.0")
  - .long_about("Checks that the given wasm file compiles successfully")
  + .long_about("Checks the given wasm file (memories, exports, imports, supported features, and non-determinism).")
  .author("Mauro Lacy <mauro@lacy.com.es>")
  .arg(
  Arg::with_name("WASM")
  @@ -32,5 +32,5 @@ pub fn main() {
  // Compile module
  compile(&wasm, None).unwrap();
  - println!("module compiled successfully")
  + println!("contract checks passed.")
  }
  