bug: 'capacitor copy ios' wont run if there is linter warning using 'capacitor run ios -l'

# Bug Report

## Capacitor Version

`npx cap doctor` output:
Latest Dependencies:

@capacitor/cli: 1.2.1

@capacitor/core: 1.2.1

@capacitor/android: 1.2.1

@capacitor/ios: 1.2.1

Installed Dependencies:

@capacitor/cli 1.2.1

@capacitor/core 1.2.1

@capacitor/android 1.2.1

@capacitor/ios 1.2.1

[success] Android looking great! 👌
Found 1 Capacitor plugin for ios:
phonegap-plugin-barcodescanner (8.1.0)
[success] iOS looking great! 👌

## Affected Platform(s)

- [ ] Android (Not sure)
- [x] iOS
- [ ] Electron (Not sure)
- [ ] Web (Not sure)

## Current Behavior
run ``ionic capacitor run ios -l --address=0.0.0.0``

``capacitor copy ios`` won't run if there is linter warning, for example:
``
> react-scripts start
[react-scripts] Attempting to bind to HOST environment variable: 0.0.0.0
[react-scripts] If this was unintentional, check that you haven't mistakenly set it in your shell.
[react-scripts] Learn more here: https://bit.ly/CRA-advanced-config
[react-scripts] Starting the development server...
[react-scripts]
[react-scripts] Compiled with warnings.
[react-scripts]
[react-scripts] ./node_modules/@angular/core/fesm5/core.js
[react-scripts] Critical dependency: the request of a dependency is an expression
[react-scripts] ./node_modules/@angular/core/fesm5/core.js
[react-scripts] Critical dependency: the request of a dependency is an expression
[react-scripts] ./node_modules/@angular/core/fesm5/core.js
[react-scripts] System.import() is deprecated and will be removed soon. Use import() instead.
[react-scripts] For more info visit https://webpack.js.org/guides/code-splitting/
[react-scripts] ./node_modules/@angular/core/fesm5/core.js
[react-scripts] System.import() is deprecated and will be removed soon. Use import() instead.
[react-scripts] For more info visit https://webpack.js.org/guides/code-splitting/
[react-scripts] Search for the keywords to learn more about each warning.
[react-scripts] To ignore, add // eslint-disable-next-line to the line before.
``

## Expected Behavior
``capacitor copy ios`` will run even if there is linter warning.

## Reproduction Steps
I am using Ionic React Typescript Capacitor.
If there is linter warning, for example,
``System.import() is deprecated and will be removed soon. Use import() instead.``
or
``Line 5:10: 'xxx' is defined but never used @typescript-eslint/no-unused-vars``
When I tried to start a development server and run on iOS with live reload with``ionic capacitor run ios -l --address=0.0.0.0``

capacitor copy ios will not run.
The local development server is started though. I can verify it on my browser.

Also, if there is no linter warning, the same command will be able to copy ios successfully and start run on iOS with live reload.

Note that ``ionic capacitor run ios`` is able to run copy ios even if there is linter warning.

`npm --version` output:
6.9.0
`node --version` output:
v10.16.3
`pod --version` output (iOS issues only):
1.8.3