style(rubocop): Style/StringLiterals

spec/lib/postal/message_db/connection_pool_spec.rb

@@ -6,8 +6,8 @@ describe Postal::MessageDB::ConnectionPool do
 
   subject(:pool) { described_class.new }
 
-  describe '#use' do
-    it 'yields a connection' do
+  describe "#use" do
+    it "yields a connection" do
       counter = 0
       pool.use do |connection|
         expect(connection).to be_a Mysql2::Client
@@ -16,7 +16,7 @@ describe Postal::MessageDB::ConnectionPool do
       expect(counter).to eq 1
     end
 
-    it 'checks in a connection after the block has executed' do
+    it "checks in a connection after the block has executed" do
       connection = nil
       pool.use do |c|
         expect(pool.connections).to be_empty
@@ -25,7 +25,7 @@ describe Postal::MessageDB::ConnectionPool do
       expect(pool.connections).to eq [connection]
     end
 
-    it 'checks in a connection if theres an error in the block' do
+    it "checks in a connection if theres an error in the block" do
       expect do
         pool.use do |c|
           raise StandardError
@@ -34,7 +34,7 @@ describe Postal::MessageDB::ConnectionPool do
       expect(pool.connections).to match [kind_of(Mysql2::Client)]
     end
 
-    it 'does not check in connections when there is a connection error' do
+    it "does not check in connections when there is a connection error" do
       expect do
         pool.use do
           raise Mysql2::Error, "lost connection to server"