Fix typos (#398)

Found via `typos --format brief`

tests/ruby/admin_spec.rb

@@ -37,9 +37,9 @@ describe "Admin" do
   describe "SHOW POOLS" do
     context "bad credentials" do
       it "does not change any stats" do
-        bad_passsword_url = URI(pgcat_conn_str)
-        bad_passsword_url.password = "wrong"
-        expect { PG::connect("#{bad_passsword_url.to_s}?application_name=bad_password") }.to raise_error(PG::ConnectionBad)
+        bad_password_url = URI(pgcat_conn_str)
+        bad_password_url.password = "wrong"
+        expect { PG::connect("#{bad_password_url.to_s}?application_name=bad_password") }.to raise_error(PG::ConnectionBad)
 
         sleep(1)
         admin_conn = PG::connect(processes.pgcat.admin_connection_string)

tests/ruby/load_balancing_spec.rb

@@ -65,7 +65,7 @@ describe "Least Outstanding Queries Load Balancing" do
     processes.pgcat.shutdown
   end
 
-  context "under homogenous load" do
+  context "under homogeneous load" do
     it "balances query volume between all instances" do
       conn = PG.connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
 

tests/ruby/sharding_spec.rb

@@ -27,7 +27,7 @@ describe "Sharding" do
     processes.pgcat.shutdown
   end
 
-  describe "automatic routing of extended procotol" do
+  describe "automatic routing of extended protocol" do
     it "can do it" do
       conn = PG.connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
       conn.exec("SET SERVER ROLE TO 'auto'")