tests: Fix test suite

Introduce a new GcalStubCalendar class that essentially
removes the ECalClient initialization from GcalCalendar,
and use it as part of a new private library consumed by
the tests.

tests/meson.build

@@ -1,6 +1,3 @@
-test_deps = gcal_deps + [ libgcal_dep ]
-
-
 test_env = [
          'G_TEST_SRCDIR=' + meson.current_source_dir(),
        'G_TEST_BUILDDIR=' + meson.current_build_dir(),
@@ -11,6 +8,27 @@ test_env = [
 
 test_cflags = '-DTEST_DATA_DIR="@0@"'.format(join_paths(meson.source_root(), 'data'))
 
+################
+# libgcal-test #
+################
+
+sources = files(
+  'gcal-stub-calendar.c',
+)
+
+libgcal_test = shared_library(
+               'gcal-test-private',
+              sources: sources,
+  include_directories: calendar_incs,
+         dependencies: libgcal_dep,
+              install: false,
+)
+
+libgcal_test_dep = declare_dependency(
+            link_with: libgcal_test,
+         dependencies: libgcal_dep,
+  include_directories: calendar_incs,
+)
 
 #########
 # Event #
@@ -19,9 +37,8 @@ test_cflags = '-DTEST_DATA_DIR="@0@"'.format(join_paths(meson.source_root(), 'da
 test_event = executable(
      'test-event',
     ['test-event.c', compiled_schemas],
-               c_args: test_cflags,
-         dependencies: test_deps,
-  include_directories: calendar_incs,
+        c_args: test_cflags,
+  dependencies: libgcal_test_dep,
 )
 
 test('test-event', test_event, env: test_env)
@@ -34,9 +51,8 @@ test('test-event', test_event, env: test_env)
 test_manager = executable(
      'test-manager',
     ['test-manager.c', compiled_schemas],
-               c_args: test_cflags,
-         dependencies: test_deps,
-  include_directories: calendar_incs,
+        c_args: test_cflags,
+  dependencies: libgcal_test_dep,
 )
 
 test('test-manager', test_manager, env: test_env)