ENH: Collections (update) (#40)

Fixes #36

app/validations/collection.js

@@ -0,0 +1,16 @@
+import {
+  validatePresence,
+  validateNumber,
+} from 'ember-changeset-validations/validators';
+
+export default {
+  project:             validatePresence(true),
+  studyLocation:       validatePresence(true),
+  collectionMethod:    validatePresence(true),
+  collectionType:      validatePresence(true),
+  numberOfTraps:       validateNumber({ allowBlank: true, integer: true, positive: true }),
+
+  collectionStartDate: validatePresence(true),
+  collectionEndDate:   validatePresence(true),
+  // TODO: Fix time formats
+}