title: pub get failed: Because flutter_app depends on firebase_firestore ^0.12.7+1 which doesn't match any versions, version solving failed
body: <blockquote>
  <pre><code> pub get failed: Because flutter_app depends on firebase_firestore
   ^0.12.7+1 which doesn't match any versions, version solving failed.
  </code></pre>
  </blockquote>
  
  <p>I am getting this error when trying to run <code>flutter pub get</code> in the pubspec.yaml file. I am currently trying to set up firebase <a href="https://firebase.google.com/docs/flutter/setup" rel="noreferrer">https://firebase.google.com/docs/flutter/setup</a>.</p>
  
  <p>This is my pubspec.yaml file:</p>
  
  <pre><code>name: flutter_app
  description: A new Flutter application.
  
  version: 1.0.0+1
  
  environment:
    sdk: "&gt;=2.1.0 &lt;3.0.0"
  
  dependencies:
    flutter:
      sdk: flutter
  
    # The following adds the Cupertino Icons font to your application.
    # Use with the CupertinoIcons class for iOS style icons.
    cupertino_icons: ^0.1.2
  
    # Add the dependency for the Firebase Core Flutter SDK
    firebase_core: ^0.4.0+1
  
    # Add the dependency for the FlutterFire plugin for Google Analytics
    firebase_analytics: ^4.0.2
  
    # Add the dependencies for any other Firebase products you want to use in your app
    # For example, to use Firebase Authentication and Cloud Firestore
    firebase_auth: ^0.11.1+3
    firebase_firestore: ^0.12.7+1
  
  dev_dependencies:
    flutter_test:
      sdk: flutter
  
  
  # For information on the generic Dart part of this file, see the
  # following page: https://dart.dev/tools/pub/pubspec
  
  # The following section is specific to Flutter.
  flutter:
  
    # The following line ensures that the Material Icons font is
    # included with your application, so that you can use the icons in
    # the material Icons class.
    uses-material-design: true
  </code></pre>
  
  <p>build.gradle:</p>
  
  <pre><code>buildscript {
      repositories {
          google()
          jcenter()
      }
  
      dependencies {
          classpath 'com.android.tools.build:gradle:3.2.1'
  
          classpath 'com.google.gms:google-services:3.2.1'
      }
  }
  
  allprojects {
      repositories {
          google()
          jcenter()
      }
  }
  
  rootProject.buildDir = '../build'
  subprojects {
      project.buildDir = "${rootProject.buildDir}/${project.name}"
  }
  subprojects {
      project.evaluationDependsOn(':app')
  }
  
  task clean(type: Delete) {
      delete rootProject.buildDir
  }
  </code></pre>
  
  <p>build.gradle app:</p>
  
  <pre><code>def localProperties = new Properties()
  def localPropertiesFile = rootProject.file('local.properties')
  if (localPropertiesFile.exists()) {
      localPropertiesFile.withReader('UTF-8') { reader -&gt;
          localProperties.load(reader)
      }
  }
  
  def flutterRoot = localProperties.getProperty('flutter.sdk')
  if (flutterRoot == null) {
      throw new GradleException("Flutter SDK not found. Define location with flutter.sdk in the local.properties file.")
  }
  
  def flutterVersionCode = localProperties.getProperty('flutter.versionCode')
  if (flutterVersionCode == null) {
      flutterVersionCode = '1'
  }
  
  def flutterVersionName = localProperties.getProperty('flutter.versionName')
  if (flutterVersionName == null) {
      flutterVersionName = '1.0'
  }
  
  apply plugin: 'com.android.application'
  apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"
  
  android {
      compileSdkVersion 28
  
      lintOptions {
          disable 'InvalidPackage'
      }
  
      defaultConfig {
          // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
          applicationId "com.example.flutter_app"
          minSdkVersion 16
          targetSdkVersion 28
          versionCode flutterVersionCode.toInteger()
          versionName flutterVersionName
          testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
      }
  
      buildTypes {
          release {
              // TODO: Add your own signing config for the release build.
              // Signing with the debug keys for now, so `flutter run --release` works.
              signingConfig signingConfigs.debug
          }
      }
  }
  
  flutter {
      source '../..'
  }
  
  dependencies {
      testImplementation 'junit:junit:4.12'
      androidTestImplementation 'androidx.test:runner:1.1.1'
      androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.1'
  }
  
  apply plugin: 'com.google.gms.google-services'
  </code></pre>
  
  <p>I have noticed that the second build.gradle file contains several marked errors, but I am not sure if that means anything. </p>
  
  <p>Thank you for your help!</p>