little cleanup + new strat

src/models/target.rs

@@ -0,0 +1,13 @@
+use crate::models::base::Base;
+
+#[derive(Copy, Clone)]
+pub struct Target {
+    pub base: Base,
+    pub required_bits: u32,
+}
+
+impl Target {
+    pub fn new(base: Base, required_bits: u32) -> Target {
+        return Target {base, required_bits};
+    }
+}