Add and apply RSpec/IncludeExamples rubocop rule

This rule was added in rubocop-rspec 3.6. We were already following it
most of the time.

.rubocop.yml

@@ -624,6 +624,9 @@ RSpec/Focus:
 RSpec/HookArgument:
   Enabled: true
 
+RSpec/IncludeExamples:
+  Enabled: true
+
 RSpec/InstanceVariable:
   Enabled: true
   Exclude:

spec/system/legislation/processes_spec.rb

@@ -146,7 +146,7 @@ describe "Legislation" do
 
   context "process page" do
     context "show" do
-      include_examples "not published permissions", :legislation_process_path
+      it_behaves_like "not published permissions", :legislation_process_path
 
       scenario "show view has document present on all phases" do
         process = create(:legislation_process)
@@ -311,7 +311,7 @@ describe "Legislation" do
         expect(page).not_to have_content("This phase is not open yet")
       end
 
-      include_examples "not published permissions", :debate_legislation_process_path
+      it_behaves_like "not published permissions", :debate_legislation_process_path
     end
 
     context "draft publication phase" do
@@ -331,7 +331,7 @@ describe "Legislation" do
         expect(page).to have_content("Nothing published yet")
       end
 
-      include_examples "not published permissions", :draft_publication_legislation_process_path
+      it_behaves_like "not published permissions", :draft_publication_legislation_process_path
     end
 
     context "allegations phase" do
@@ -355,7 +355,7 @@ describe "Legislation" do
         expect(page).to have_content("Nothing published yet")
       end
 
-      include_examples "not published permissions", :allegations_legislation_process_path
+      it_behaves_like "not published permissions", :allegations_legislation_process_path
     end
 
     context "final version publication phase" do
@@ -375,7 +375,7 @@ describe "Legislation" do
         expect(page).to have_content("Nothing published yet")
       end
 
-      include_examples "not published permissions", :result_publication_legislation_process_path
+      it_behaves_like "not published permissions", :result_publication_legislation_process_path
     end
 
     context "proposals phase" do
@@ -395,7 +395,7 @@ describe "Legislation" do
         expect(page).to have_content("There are no proposals")
       end
 
-      include_examples "not published permissions", :legislation_process_proposals_path
+      it_behaves_like "not published permissions", :legislation_process_proposals_path
     end
 
     context "Milestones" do