Refactor parts of the code and add more tests

This is a refactor of parts of the code, some minor things such as adding
punctuation in the end of sentences and making the code a bit easier to read.

More tests has been added in the form of gometalinter which checks the code
health, style and spelling errors. The flaky cleanup test should also be fixed
with this commit.

cleanup_test.go

@@ -8,14 +8,14 @@ import (
 )
 
 func TestCleanup(t *testing.T) {
-	ss, err := NewPGStore(os.Getenv("PGSTORE_TEST_CONN"), []byte(secret))
-
-	if err != nil {
-		t.Fatal("Failed to get store", err)
+	dsn := os.Getenv("PGSTORE_TEST_CONN")
+	if dsn == "" {
+		t.Skip("This test requires a real database.")
 	}
 
-	if ss == nil {
-		t.Skip("This test requires a real database")
+	ss, err := NewPGStore(dsn, []byte(secret))
+	if err != nil {
+		t.Fatal("Failed to get store", err)
 	}
 
 	defer ss.Close()
@@ -32,7 +32,7 @@ func TestCleanup(t *testing.T) {
 		t.Fatal("Failed to create session", err)
 	}
 
-	// Expire the session
+	// Expire the session.
 	session.Options.MaxAge = 1
 
 	m := make(http.Header)
@@ -40,8 +40,8 @@ func TestCleanup(t *testing.T) {
 		t.Fatal("failed to save session:", err.Error())
 	}
 
-	// Give the ticker a moment to run
-	time.Sleep(time.Second * 1)
+	// Give the ticker a moment to run.
+	time.Sleep(time.Millisecond * 1500)
 
 	// SELECT expired sessions. We should get a zero-length result slice back.
 	var results []int64