Bump to 1.2.0

Changes:
- Use Spree::Store when looking for Spree::Tracker.current

solidus_multi_domain.gemspec

@@ -3,7 +3,7 @@
 Gem::Specification.new do |s|
   s.platform    = Gem::Platform::RUBY
   s.name        = "solidus_multi_domain"
-  s.version     = "1.1.3"
+  s.version     = "1.2.0"
   s.summary     = "Adds multiple site support to Solidus"
   s.description = "Multiple Solidus stores on different domains - single unified backed for processing orders."
   s.required_ruby_version = ">= 2.1"