fix: generic stop

Author: richardschneider

src/core/components/stop.js

@@ -13,6 +13,10 @@ module.exports = (self) => {
       return callback(new Error('Already stopped'))
     }
 
+    if (self.state.state() !== 'running') {
+      return callback(new Error('Not able to stop from state: ' + self.state.state()))
+    }
+
     const done = (err) => {
       if (err) {
         self.emit('error', err)

test/core/interface/generic.js

@@ -26,7 +26,7 @@ const common = {
     })
   },
   teardown: function (callback) {
-    // Stopped by the tests themselves
+    // No need to stop, because the test suite does a 'stop' test.
     // parallel(nodes.map((node) => (cb) => node.stop(cb)), callback)
     callback()
   }