Firebase dependencies are outdated.

[success-0627]

[!] CocoaPods could not find compatible versions for pod "FirebaseDatabase":
In Podfile:
Firebase/Database was resolved to 6.6.0, which depends on
FirebaseDatabase (~> 6.0.0)

RxFirebase/Database (from `https://github.com/RxSwiftCommunity/RxFirebase`, commit `7fa6cf69e79af485858509fc93103aad1348fa69`) was resolved to 0.3.7, which depends on
  RxFirebaseDatabase (~> 0.3) was resolved to 0.3.7, which depends on
    FirebaseDatabase (~> 5)

[success-0627]

I think this PR is solution and when would you like to merge ?

[success-0627]

[!] CocoaPods could not find compatible versions for pod "FirebaseCore":
In Podfile:
RxFirebase/Database (from https://github.com/RxSwiftCommunity/RxFirebase.git, branch develop) was resolved to 0.3.8, which depends on
RxFirebaseDatabase (> 0.3) was resolved to 0.3.7, which depends on
FirebaseDatabase (> 5) was resolved to 5.1.1, which depends on
FirebaseCore (~> 5.2)

[success-0627]

Please check this.
firebase/FirebaseUI-iOS#722
This library needs to be updated, otherwise how could we keep using this library with outdated dependencies?

[arnauddorgans]

I working on it, 0.3.8 will be available soon :)

[arnauddorgans]

Available :)

[success-0627]

You are my hero

[arnauddorgans]

Sorry for the delay guys