Make ablescript -f run interpreter

`ablescript -f foo.able` will now both parse and interpret `foo.able`,
rather than just parsing it.

src/main.rs

@@ -10,6 +10,7 @@ mod repl;
 mod variables;
 
 use clap::{App, Arg};
+use interpret::Scope;
 use logos::Source;
 use parser::Parser;
 
@@ -38,7 +39,11 @@ fn main() {
             let mut parser = Parser::new(&source);
             let ast = parser.init();
             match ast {
-                Ok(ast) => println!("{:#?}", ast),
+                Ok(ast) => {
+                    println!("{:#?}", ast);
+                    let mut ctx = Scope::new();
+                    println!("{:?}", ctx.eval_items(&ast));
+                }
                 Err(e) => {
                     println!(
                         "Error `{:?}` occured at span: {:?} = `{:?}`",