Restructure tests into separate modules

Move all tests to a designated subdirectory and split the modules up
so that each test module covers one module.

Further rename some misnamed Test classes and adapt the test coverage
configuration so that the new test modules are omitted in the reports.

Issue: HIC-212
Change-Id: Idfa309aad34b8adae181cc76e95b67a86231bc69
diff --git a/crashreports/tests/__init__.py b/crashreports/tests/__init__.py
new file mode 100644
index 0000000..4b3e347
--- /dev/null
+++ b/crashreports/tests/__init__.py
@@ -0,0 +1 @@
+"""Tests for the crashreports modules."""