test(screenshotter): move coverage to Jest (#2324)

* Move screenshotter coverage collection to Jest testing

Fixes #1885.

* Update screenshotter-spec.js

* Update screenshotter-spec.js

Co-authored-by: Kevin Barabash <kevinb@khanacademy.org>

test/screenshotter-spec.js

@@ -0,0 +1,19 @@
+const data = require("./screenshotter/ss_data");
+
+describe("Screenshotter item", function() {
+    for (const key in data) {
+        if (data.hasOwnProperty(key)) {
+            const item = data[key];
+            it(`"${item.tex}" should build successfully`, function() {
+                expect(item.tex).toBuild({
+                    macros: item.macros,
+                    displayMode: item.display,
+                    throwOnError: !item.noThrow,
+                    errorColor: item.errorColor,
+                    strict: false,
+                    trust: true,  // trust test inputs
+                });
+            });
+        }
+    }
+});