Update dependency versions inside gemspec

Author: apuntamb

fog-azure-rm.gemspec

@@ -22,8 +22,8 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency 'minitest', '~> 5.8.4'
   spec.add_development_dependency 'simplecov'
   spec.add_development_dependency 'codeclimate-test-reporter' , '~> 1.0.0'
-  spec.add_dependency 'fog-core', '~> 1.43'
-  spec.add_dependency 'fog-json', '~> 1.0.2'
+  spec.add_dependency 'fog-core'
+  spec.add_dependency 'fog-json'
   spec.add_dependency 'azure_mgmt_compute', '~> 0.9.0'
   spec.add_dependency 'azure_mgmt_resources', '~> 0.9.0'
   spec.add_dependency 'azure_mgmt_storage', '~> 0.9.0'
@@ -32,7 +32,7 @@ Gem::Specification.new do |spec|
   spec.add_dependency 'azure_mgmt_traffic_manager', '~> 0.9.0'
   spec.add_dependency 'azure_mgmt_sql', '~> 0.9.0'
   spec.add_dependency 'azure_mgmt_key_vault', '~> 0.9.0'
-  spec.add_dependency 'azure-storage', '= 0.11.5.preview'
+  spec.add_dependency 'azure-storage', '~> 0.11.preview'
   spec.add_dependency 'vhd', '0.0.4'
-  spec.add_dependency 'mime-types', '~> 1.25'
+  spec.add_dependency 'mime-types', '> 1.25', '< 4.0'
 end