Update `semver`, use `^` instead of `~`

package.json

@@ -30,8 +30,8 @@
   },
   "homepage": "https://github.com/creationix/nvm",
   "devDependencies": {
-    "replace": "~0.3.0",
-    "semver": "~4.2.0",
-    "urchin": "~0.0.5"
+    "replace": "^0.3.0",
+    "semver": "^4.3.3",
+    "urchin": "^0.0.5"
   }
 }