Minor fixes (#2038)

Fixes a couple of low hanging fruits.

- Fixes #2037 
- `validators-dir` and `secrets-dir` flags don't really need to depend upon each other
- Fixes #2006 and Fixes #1995

beacon_node/eth1/tests/test.rs

@@ -521,7 +521,7 @@ mod deposit_tree {
                 .map(|raw| raw.to_deposit_log(spec).expect("should parse deposit log"))
                 .inspect(|log| {
                     tree.insert_log(log.clone())
-                        .expect("should add consecutive logs")
+                        .expect("should add consecutive logs");
                 })
                 .collect();