bump iOS version in podspec/Fabric

ios/Mapbox-iOS-SDK.podspec

@@ -1,7 +1,7 @@
 Pod::Spec.new do |m|
 
   m.name    = 'Mapbox-iOS-SDK'
-  m.version = '3.0.0-pre.2-symbols'
+  m.version = '3.0.0-pre.3-symbols'
 
   m.summary          = 'Open source vector map solution for iOS with full styling capabilities.'
   m.description      = 'Open source OpenGL-based vector map solution for iOS with full styling capabilities and Cocoa bindings.'

platform/ios/MGLAccountManager.m

@@ -80,7 +80,7 @@
 }
 
 + (NSString *)kitDisplayVersion {
-    return @"3.0.0-pre.2";
+    return @"3.0.0-pre.3";
 }
 
 + (void)initializeIfNeeded {