fix: xcode 10.2 compatibility for run-ios command

parse output of simulator list provided by xcode 10.2

In Xcode 10.2, the output of `xcrun simctl list --json devices`
has changed to include a namespace within each version group.
This commit makes a backwards-compatible adjustment to account
for this change in format.

To illustrate:

```
{
  "devices": {
    "iOS 10.0": [
      ...
    ]
  }
}
```

```
{
  "devices": {
    "com.apple.CoreSimulator.SimRuntime.iOS 10.0": [
      ...
    ]
  }
}
```

Author: canterberry

Diff for: packages/cli/src/runIOS/findMatchingSimulator.js

@@ -39,7 +39,9 @@ function findMatchingSimulator(simulators, simulatorString) {
   }
 
   let match;
-  for (const version in devices) {
+  for (const versionDescriptor in devices) {
+    const version = versionDescriptor.replace(/^com\.apple\.CoreSimulator\.SimRuntime\./g, '');
+
     // Making sure the version of the simulator is an iOS or tvOS (Removes Apple Watch, etc)
     if (!version.startsWith('iOS') && !version.startsWith('tvOS')) {
       continue;