Android app and library dependencies clash

my app uses these dependencies

 compile 'com.android.support:appcompat-v7:22.2.1'
 compile 'com.android.support:design:22.2.1'
 compile 'com.google.android.gms:play-services:7.0.0'
 compile 'com.google.code.gson:gson:2.2.4'

when i imported seek arc library it uses different dependencies

  compile 'com.android.support:appcompat-v7:23.4.0'
  compile 'com.android.support:appcompat-v7:23.2.1'
  compile 'com.android.support:design:23.2.1'
  compile project(':SeekArc_library')

How can i solve this problem ?