Fix the krate::downloads test

This test wasn't technically wrong, it was just very confusing. The
`assert_dl_count` function was testing the length of the array returned
by the downloads endpoint. When we test that case insensitivity works,
this makes it look like there's a bug, since we'd intuitively expect
`assert_dl_count` expect 2 downloads. But it wasn't testing the number
of downloads, it was testing the number of records we returned (one
record per version per day that there were downloads). So the JSON we
returned was correct:

    [
      {
        "version_id": 1,
        "date": "2018-10-30",
        "downloads": 2,
      }
    ]

But the test didn't really reflect what we expected. This changes it to
actually test the sum of the "downloads" field, which is intuitively
what you'd expect this to be testing.

Author: sgrif

src/tests/krate.rs

@@ -1185,14 +1185,17 @@ fn download() {
             .expect_build(&conn);
     });
 
-    let assert_dl_count = |name_and_version: &str, query: Option<&str>, count: usize| {
+    let assert_dl_count = |name_and_version: &str, query: Option<&str>, count: i32| {
         let url = format!("/api/v1/crates/{}/downloads", name_and_version);
         let downloads: Downloads = if let Some(query) = query {
             anon.get_with_query(&url, query).good()
         } else {
             anon.get(&url).good()
         };
-        assert_eq!(downloads.version_downloads.len(), count);
+        let total_downloads = downloads.version_downloads.iter()
+            .map(|vd| vd.downloads)
+            .sum::<i32>();
+        assert_eq!(total_downloads, count);
     };
 
     let download = |name_and_version: &str| {
@@ -1206,20 +1209,19 @@ fn download() {
     assert_dl_count("foo_download", None, 1);
 
     download("FOO_DOWNLOAD/1.0.0");
-    assert_dl_count("FOO_DOWNLOAD/1.0.0", None, 1);
-    assert_dl_count("FOO_DOWNLOAD", None, 1);
-    // TODO: Is the behavior above a bug?
+    assert_dl_count("FOO_DOWNLOAD/1.0.0", None, 2);
+    assert_dl_count("FOO_DOWNLOAD", None, 2);
 
     let yesterday = (Utc::today() + Duration::days(-1)).format("%F");
     let query = format!("before_date={}", yesterday);
     assert_dl_count("FOO_DOWNLOAD/1.0.0", Some(&query), 0);
     // crate/downloads always returns the last 90 days and ignores date params
-    assert_dl_count("FOO_DOWNLOAD", Some(&query), 1);
+    assert_dl_count("FOO_DOWNLOAD", Some(&query), 2);
 
     let tomorrow = (Utc::today() + Duration::days(1)).format("%F");
     let query = format!("before_date={}", tomorrow);
-    assert_dl_count("FOO_DOWNLOAD/1.0.0", Some(&query), 1);
-    assert_dl_count("FOO_DOWNLOAD", Some(&query), 1);
+    assert_dl_count("FOO_DOWNLOAD/1.0.0", Some(&query), 2);
+    assert_dl_count("FOO_DOWNLOAD", Some(&query), 2);
 }
 
 #[test]