diff --git a/.travis.yml b/.travis.yml
index 7a64549e..08922270 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -21,8 +21,8 @@ rvm:
 #  - 2.3.1
 #script: bundle exec rspec --color --format documentation --require spec_helper --require rails_helper --tag ~docker
 
-  - 2.1.5
-  - 2.2.1
+#  - 2.1.5
+#  - 2.2.1
   - 2.3.1
-script: bundle exec rspec --require spec_helper --require rails_helper --tag ~docker
+script: bundle exec rspec --color --format documentation --require spec_helper --require rails_helper
 
diff --git a/app/controllers/submissions_controller.rb b/app/controllers/submissions_controller.rb
index e236ebeb..baf08cae 100644
--- a/app/controllers/submissions_controller.rb
+++ b/app/controllers/submissions_controller.rb
@@ -271,7 +271,7 @@ class SubmissionsController < ApplicationController
 
   def stop
     Rails.logger.debug('stopping submission ' + @submission.id.to_s)
-    container = Docker::Container.get(params[:containtier_id])
+    container = Docker::Container.get(params[:container_id])
     DockerClient.destroy_container(container)
   rescue Docker::Error::NotFoundError
   ensure
diff --git a/lib/docker_client.rb b/lib/docker_client.rb
index f6fb9e2c..9d2f30b6 100644
--- a/lib/docker_client.rb
+++ b/lib/docker_client.rb
@@ -25,10 +25,9 @@ class DockerClient
     #container.exec(['bash', '-c', 'rm -rf ' + CONTAINER_WORKSPACE_PATH + '/*'])
 
     local_workspace_path = local_workspace_path(container)
-    path_to_delete = Pathname.new(local_workspace_path)
-    if local_workspace_path ||  Pathname.new(local_workspace_path).exist?
-      path_to_delete.children.each{ |p| p.rmtree}
-      #FileUtils.rmdir(path_to_delete)
+    if local_workspace_path &&  Pathname.new(local_workspace_path).exist?
+      Pathname.new(local_workspace_path).children.each{ |p| p.rmtree}
+      #FileUtils.rmdir(Pathname.new(local_workspace_path))
     end
   end
 
@@ -193,8 +192,6 @@ class DockerClient
     if(container)
       container.delete(force: true, v: true)
     end
-    local_workspace_path(container)
-
   rescue Docker::Error::NotFoundError => error
     Rails.logger.error('destroy_container: Rescued from Docker::Error::NotFoundError: ' + error.to_s)
     Rails.logger.error('No further actions are done concerning that.')
@@ -332,11 +329,13 @@ class DockerClient
     Docker::Image.all.map { |image| image.info['RepoTags'] }.flatten.reject { |tag| tag.include?('<none>') }
   end
 
-# When @image commented test doesn't work
+# When @image commented test doesn't work -> test set to pending
   def initialize(options = {})
     @execution_environment = options[:execution_environment]
-    @image = self.class.find_image_by_tag(@execution_environment.docker_image)
-    fail(Error, "Cannot find image #{@execution_environment.docker_image}!") unless @image
+    # todo: eventually re-enable this if it is cached. But in the end, we do not need this.
+    # docker daemon got much too much load. all not 100% necessary calls to the daemon were removed.
+    #@image = self.class.find_image_by_tag(@execution_environment.docker_image)
+    #fail(Error, "Cannot find image #{@execution_environment.docker_image}!") unless @image
   end
 
   def self.initialize_environment
diff --git a/lib/xikolo/client.rb b/lib/xikolo/client.rb
index 66fab666..06e4ecf4 100644
--- a/lib/xikolo/client.rb
+++ b/lib/xikolo/client.rb
@@ -56,4 +56,4 @@ class Xikolo::Client
   def self.authentication_url
     return @url + 'authenticate'
   end
-end
+end
\ No newline at end of file
diff --git a/spec/policies/execution_environment_policy_spec.rb b/spec/policies/execution_environment_policy_spec.rb
index 8bede9e1..799881b5 100644
--- a/spec/policies/execution_environment_policy_spec.rb
+++ b/spec/policies/execution_environment_policy_spec.rb
@@ -21,8 +21,7 @@ describe ExecutionEnvironmentPolicy do
     end
   end
 
-
-  [:execute_command?, :shell?, :statistics?].each do |action|
+  [:destroy?, :edit?, :execute_command?, :shell?, :show?, :update?].each do |action|
     permissions(action) do
       it 'grants access to admins' do
         expect(subject).to permit(FactoryGirl.build(:admin), execution_environment)
@@ -39,22 +38,4 @@ describe ExecutionEnvironmentPolicy do
       end
     end
   end
-
-  [:destroy?, :edit?, :show?, :update?].each do |action|
-    permissions(action) do
-      it 'grants access to admins' do
-        expect(subject).to permit(FactoryGirl.build(:admin), execution_environment)
-      end
-
-      it 'does not grant access to authors' do
-        expect(subject).not_to permit(execution_environment.author, execution_environment)
-      end
-
-      it 'does not grant access to all other users' do
-        [:external_user, :teacher].each do |factory_name|
-          expect(subject).not_to permit(FactoryGirl.build(factory_name), execution_environment)
-        end
-      end
-    end
-  end
 end
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 320310a2..0ea8706a 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -15,9 +15,6 @@
 #
 # See http://rubydoc.info/gems/rspec-core/RSpec/Core/Configuration
 
-require "codeclimate-test-reporter"
-CodeClimate::TestReporter.start
-
 unless RUBY_PLATFORM == 'java'
   if ENV['CODECLIMATE_REPO_TOKEN']
     require 'codeclimate-test-reporter'
@@ -28,9 +25,6 @@ unless RUBY_PLATFORM == 'java'
   end
 end
 
-require 'selenium-webdriver'
-#Selenium::WebDriver::Firefox::Binary.path='/usr/bin/firefox'
-
 RSpec.configure do |config|
   # These two settings work together to allow you to limit a spec run
   # to individual examples or groups you care about by tagging them with
@@ -39,11 +33,6 @@ RSpec.configure do |config|
   config.filter_run :focus
   config.run_all_when_everything_filtered = true
 
-
-  #for --next-failure feature purpose
-  config.example_status_persistence_file_path = "examples.txt"
-  config.run_all_when_everything_filtered = true
-
   # Many RSpec users commonly either run the entire suite or an individual
   # file, and it's useful to allow more verbose output when running an
   # individual spec file.