deps: replace level with levelup and leveldown

level only allows for leveldown and isn't actually used. the project
requires levelup directly wich is installed by level.

Semver: minor

lib/timer.js

@@ -13,7 +13,7 @@
 const os             = require('os')
     , crypto         = require('crypto')
     , path           = require('path')
-    , level          = require('levelup')
+    , levelup        = require('levelup')
     , encode         = require('encoding-down')
     , Transports     = require('./transports')
     , nats           = require('./nats')
@@ -105,7 +105,7 @@ class Timer extends Map {
     this[kNode] = generateId(store_opts.path)
     this.nats = nats.createClient( this.options.nats );
     this.transports = new Transports(this.options.transports);
-    this[storage] = level(backend, opts, (err) => {
+    this[storage] = levelup(backend, opts, (err) => {
       store('storage backend ready', store_opts);
       debug('node id', this[kNode])
       this.recover(() => {

package.json

@@ -7,7 +7,7 @@
     "skyring": "./bin/skyring.js"
   },
   "scripts": {
-    "test": "tap --cov -Rtap test",
+    "test": "npm run check && tap --cov -Rtap test",
     "coverage": "tap --coverage-report=text-lcov | ./node_modules/.bin/codeclimate-test-reporter",
     "docs": "jsdoc -c jsdoc.json && apidoc -i lib/server -o docs/api",
     "check": "check-pkg -d !docs -d !node_modules -d !examples",
@@ -36,7 +36,8 @@
     "debug": "^3.1.0",
     "encoding-down": "^5.0.2",
     "keef": "^4.0.1",
-    "level": "^4.0.0",
+    "leveldown": "^4.0.1",
+    "levelup": "^3.1.1",
     "memdown": "^3.0.0",
     "nats": "^1.0.1",
     "needle": "^2.2.4",