Correct argument order in test assertions

The `testify` Go packages use the "Yoda condition"-style argument order: expected, actual. If the assertions reverse
the order of the arguments, the test failure output becomes very confusing.

Even though `assert.ElementsMatch()` doesn't treat the order of the arguments specially, it is best to be consistent
with the order.

Author: per1234

main_test.go

@@ -103,7 +103,7 @@ index cff484d..9f67763 100644
 	assert.Equal(t, "submission", requestType, testName)
 	assert.Equal(t, "", requestError, testName)
 	assert.Equal(t, "submit", arduinoLintLibraryManagerSetting, testName)
-	assert.ElementsMatch(t, submissionURLs, []string{"https://github.com/foo/bar", "https://github.com/foo/baz"}, testName)
+	assert.ElementsMatch(t, []string{"https://github.com/foo/bar", "https://github.com/foo/baz"}, submissionURLs, testName)
 
 	testName = "Submission w/ no newline at end of file"
 	diff = []byte(`
@@ -137,7 +137,7 @@ index cff484d..1b0b80b 100644
 	assert.Equal(t, "submission", requestType, testName)
 	assert.Equal(t, "", requestError, testName)
 	assert.Equal(t, "submit", arduinoLintLibraryManagerSetting, testName)
-	assert.ElementsMatch(t, submissionURLs, []string{"https://github.com/foo/bar"}, testName)
+	assert.ElementsMatch(t, []string{"https://github.com/foo/bar"}, submissionURLs, testName)
 
 	testName = "Removal"
 	diff = []byte(`
@@ -170,7 +170,7 @@ index cff484d..8b401a1 100644
 	assert.Equal(t, "modification", requestType, testName)
 	assert.Equal(t, "", requestError, testName)
 	assert.Equal(t, "update", arduinoLintLibraryManagerSetting, testName)
-	assert.Equal(t, submissionURLs, []string{"https://github.com/foo/bar"}, testName)
+	assert.Equal(t, []string{"https://github.com/foo/bar"}, submissionURLs, testName)
 }
 
 func Test_normalizeURL(t *testing.T) {