Remove unused import and uniformize crates (#686)

* Removed unused crates
* Add listconnectedpeers in grin client
* Removed unused import and uniformize crates

api/Cargo.toml

@@ -13,7 +13,7 @@ grin_util = { path = "../util" }
 grin_p2p = { path = "../p2p" }
 hyper = "~0.10.6"
 slog = { version = "^2.0.12", features = ["max_level_trace", "release_max_level_trace"] }
-lazy_static = "1.0"
+lazy_static = "~0.2.8"
 iron = "~0.5.1"
 router = "~0.5.1"
 regex = "^0.2"
@@ -21,4 +21,4 @@ mount = "~0.3.0"
 urlencoded = "~0.5.0"
 serde = "~1.0.8"
 serde_derive = "~1.0.8"
-serde_json = "~1.0.7"
+serde_json = "~1.0.9"