Check arrays are empty instead of size 0

In ruby we check for `array.empty?` instead of `array.size == 0`, so
it's natural to write the tests in the same way.

spec/lib/email_digests_spec.rb

@@ -91,7 +91,7 @@ describe EmailDigest do
       email_digest = EmailDigest.new(user)
       email_digest.deliver(Time.current)
 
-      expect(all_emails.count).to eq(0)
+      expect(all_emails).to be_empty
     end
 
   end

spec/models/custom/verification/residence_spec.rb

@@ -10,11 +10,11 @@ describe Verification::Residence do
       it "is valid with postal codes starting with 280" do
         residence.postal_code = "28012"
         residence.valid?
-        expect(residence.errors[:postal_code].size).to eq(0)
+        expect(residence.errors[:postal_code]).to be_empty
 
         residence.postal_code = "28023"
         residence.valid?
-        expect(residence.errors[:postal_code].size).to eq(0)
+        expect(residence.errors[:postal_code]).to be_empty
       end
 
       it "is not valid with postal codes not starting with 280" do

spec/models/debate_spec.rb

@@ -762,7 +762,7 @@ describe Debate do
     it "does not return any debates when user has not interests" do
       create(:debate)
 
-      expect(Debate.recommendations(user).size).to eq 0
+      expect(Debate.recommendations(user)).to be_empty
     end
 
     it "returns debates ordered by cached_votes_total" do

spec/models/officing/residence_spec.rb

@@ -91,7 +91,8 @@ describe Officing::Residence do
           custom_residence = Officing::Residence.new("date_of_birth(3i)" => "1",
                                                  "date_of_birth(2i)" => "1",
                                                  "date_of_birth(1i)" => "1980")
-          expect(custom_residence.errors[:date_of_birth].size).to eq(0)
+
+          expect(custom_residence.errors[:date_of_birth]).to be_empty
         end
 
         it "is not valid without a date of birth" do

spec/models/organization_spec.rb

@@ -48,11 +48,11 @@ describe Organization do
     let!(:organization) { create(:organization, name: "Watershed", user: create(:user, phone_number: "333")) }
 
     it "returns no results if search term is empty" do
-      expect(Organization.search(" ").size).to eq(0)
+      expect(Organization.search(" ")).to be_empty
     end
 
     it "finds fuzzily by name" do
-      expect(Organization.search("Greenpeace").size).to eq 0
+      expect(Organization.search("Greenpeace")).to be_empty
       search = Organization.search("Tershe")
       expect(search.size).to eq 1
       expect(search.first).to eq organization

spec/models/proposal_spec.rb

@@ -1000,7 +1000,7 @@ describe Proposal do
     it "does not return any proposals when user has not interests" do
       create(:proposal)
 
-      expect(Proposal.recommendations(user).size).to eq 0
+      expect(Proposal.recommendations(user)).to be_empty
     end
 
     it "returns proposals ordered by cached_votes_up" do
@@ -1034,7 +1034,7 @@ describe Proposal do
 
       result = Proposal.recommendations(user)
 
-      expect(result.size).to eq 0
+      expect(result).to be_empty
     end
 
     it "does not return proposals when user is the author" do

spec/models/user_spec.rb

@@ -448,7 +448,7 @@ describe User do
     end
 
     it "returns no results if no search term provided" do
-      expect(User.search("    ").size).to eq(0)
+      expect(User.search("    ")).to be_empty
     end
   end
 

spec/models/verification/management/document_spec.rb

@@ -74,7 +74,8 @@ describe Verification::Management::Document do
           verification_document = Verification::Management::Document.new("date_of_birth(3i)" => "1",
                                                       "date_of_birth(2i)" => "1",
                                                       "date_of_birth(1i)" => "1980")
-          expect(verification_document.errors[:date_of_birth].size).to eq(0)
+
+          expect(verification_document.errors[:date_of_birth]).to be_empty
         end
 
         it "is not valid without a date of birth" do

spec/models/verification/residence_spec.rb

@@ -14,7 +14,8 @@ describe Verification::Residence do
     describe "dates" do
       it "is valid with a valid date of birth" do
         residence = Verification::Residence.new("date_of_birth(3i)" => "1", "date_of_birth(2i)" => "1", "date_of_birth(1i)" => "1980")
-        expect(residence.errors[:date_of_birth].size).to eq(0)
+
+        expect(residence.errors[:date_of_birth]).to be_empty
       end
 
       it "is not valid without a date of birth" do