Undefined symbols for architecture armv7 in xcode, Google Play Games and AdMob

Hello there, I've been scratching my head over this for the last few days without much progress. I build my project in Unity and it's fine, move on to Xcode and it gives me the following errors:

 Undefined symbols for architecture armv7:
   "_inflate", referenced from:
       +[NSData(GTMZlibAdditionsPrivate) gtm_dataByInflatingBytes:length:isRawData:] in GoogleUtilities(GTMNSData+zlib.o)
      (maybe you meant: _unity_z_inflateGetHeader, _unity_z_inflateSetDictionary , _inflate_table , _unity_z_inflateInit2_ , _unity_z_inflatePrime , _unity_z_inflate , _unity_z_inflateReset , _unity_z_inflateInit_ , _il2cpp_class_is_inflated , __Z27scripting_class_is_inflatedP14ScriptingClass , _unity_z_inflateEnd , _il2cpp_method_is_inflated , _unity_z_inflateSyncPoint , _unity_z_inflateSync , _InfTree_inflate_trees_fixed_m2260281664_MetadataUsageId , _InfTree_inflate_trees_dynamic_m1571350987_MetadataUsageId , _InfTree_inflate_trees_fixed_m2260281664 , _unity_z_inflateCopy , _InfTree_inflate_trees_bits_m3862224992_MetadataUsageId , _inflate_fast , _InfTree_inflate_trees_bits_m3862224992 , _InfTree_inflate_trees_dynamic_m1571350987 , _inflate_copyright )
   "_deflate", referenced from:
       +[NSData(GTMZlibAdditionsPrivate) gtm_dataByCompressingBytes:length:compressionLevel:mode:] in GoogleUtilities(GTMNSData+zlib.o)
      (maybe you meant: _unity_z_deflateCopy, _unity_z_deflateTune , _unity_z_deflateInit2_ , _unity_z_deflateReset , _unity_z_deflatePrime , _unity_z_deflateSetDictionary , _unity_z_deflateEnd , _unity_z_deflate , _unity_z_deflateSetHeader , _unity_z_deflateParams , _unity_z_deflate_copyright , _unity_z_deflateInit_ , _unity_z_deflateBound )
   "_inflateEnd", referenced from:
       +[NSData(GTMZlibAdditionsPrivate) gtm_dataByInflatingBytes:length:isRawData:] in GoogleUtilities(GTMNSData+zlib.o)
      (maybe you meant: _unity_z_inflateEnd)
   "_deflateInit2_", referenced from:
       +[NSData(GTMZlibAdditionsPrivate) gtm_dataByCompressingBytes:length:compressionLevel:mode:] in GoogleUtilities(GTMNSData+zlib.o)
      (maybe you meant: _unity_z_deflateInit2_)
   "_inflateInit2_", referenced from:
       +[NSData(GTMZlibAdditionsPrivate) gtm_dataByInflatingBytes:length:isRawData:] in GoogleUtilities(GTMNSData+zlib.o)
      (maybe you meant: _unity_z_inflateInit2_)
   "_deflateEnd", referenced from:
       +[NSData(GTMZlibAdditionsPrivate) gtm_dataByCompressingBytes:length:compressionLevel:mode:] in GoogleUtilities(GTMNSData+zlib.o)
      (maybe you meant: _unity_z_deflateEnd)
   "_OBJC_CLASS_$_GIDSignIn", referenced from:
       objc-class-ref in gpg(GPGManager.o)
       objc-class-ref in gpg(GPGService.o)
       objc-class-ref in gpg(libgpg.a-armv7-master.o)
 ld: symbol(s) not found for architecture armv7
 clang: error: linker command failed with exit code 1 (use -v to see invocation)

The "OBJC_CLASS$_GIDSignIn" specifically I can't fix no matter what. The others get fixed by getting rid of the GoogleUtilities framework and since I don't need them it doesn't really affect the project. The real problem is the GoogleSignIn class.

I'm using Unity 5.4.1f1, xcode 7.3.1, Mac Os Sierra 10.12.1 and the official unity Admob plugin ver 3.1.3. Also using cocoapods to import the admob and googleplay frameworks, here it is:

 source 'https://github.com/CocoaPods/Specs.git'
 install! 'cocoapods', :integrate_targets => false
 platform :ios, '82'
 
 target 'Unity-iPhone' do
 pod 'Google-Mobile-Ads-SDK', '~> 7.13'
 pod 'GooglePlayGames', '~> 5.0'
 end

If anyone's had this problem before and can shed some light on the issues I'd really appreciate it.