Problem to install for ios

[juliocampossalcedo]

Expected Behavior

Install the plugin cordova-plugin-firebase-crashlytics version 1.2.0 for ios

Actual Behavior

I got this error:

[!] CocoaPods could not find compatible versions for pod "FirebaseCore": In snapshot (Podfile.lock): FirebaseCore (= 6.0.1, ~> 6.0)

In Podfile: Firebase/Core (~> 6.1.0) was resolved to 6.1.0, which depends on Firebase/CoreOnly (= 6.1.0) was resolved to 6.1.0, which depends on FirebaseCore (= 6.0.1)

FirebaseAnalytics was resolved to 6.0.1, which depends on
  FirebaseCore (~> 6.0)

FirebaseCrashlytics was resolved to 4.1.1, which depends on
  FirebaseCore (~> 6.6)

CocoaPods could not find compatible versions for pod "FirebaseCrashlytics": In Podfile: FirebaseCrashlytics

There are only pre-release versions available satisfying the following requirements:

'FirebaseCrashlytics', '>= 0'

You should explicitly specify the version in order to install a pre-release version

Steps to Reproduce the Problem

I forked this plugin and changed the config.xml file removing these lines:

>   <hook type="after_plugin_install" src="scripts/after_plugin_add.js" />
>   <hook type="after_platform_add" src="scripts/after_plugin_add.js" />
>   <hook type="before_plugin_uninstall" src="scripts/before_plugin_rm.js" />

Then I try to install the plugin, for android worked, but for ios I am getting this error

Specifications

• Plugin version:
• Framework:
• Framework version:
• Operating system:

[juliocampossalcedo]

I fixed this issue updating my cordova-plugin-firebase-crashlytics and cordova-plugin-firebase-config plugins