fix: make path to env files depend of the CARGO_MANIFEST_DIR of sesam-vitale crate

crates/sesam-vitale/src/ssvlib_demo.rs

@@ -3,9 +3,9 @@ extern crate dotenv;
 
 use libc::{ c_char, c_void, c_ushort, size_t };
 use std::ffi::CString;
+use std::path::PathBuf;
 use std::ptr;
 
-use dotenv::dotenv;
 use std::env;
 
 extern "C" {
@@ -72,7 +72,9 @@ fn ssv_lire_config() {
 }
 
 pub fn demo() {
-    dotenv().ok();
+    let manifest_dir = env::var("CARGO_MANIFEST_DIR").unwrap();
+    let manifest_path = PathBuf::from(manifest_dir);
+    dotenv::from_path(manifest_path.join(".env")).ok();
 
     println!("------- Demo for the SSV library --------");