Added PersistentJsonStorageClass

PersistentJsonStorage is used to store persistent information in
json format. This class will be used by ReportManager to save
persistent report configuration.

Tested:
  - Added unit tests for new functionality
  - All other unit tests are passing

Signed-off-by: Krzysztof Grobelny <krzysztof.grobelny@intel.com>
Change-Id: Ib496e6782e849d910fe37c02c355047afda5c79c
diff --git a/tests/meson.build b/tests/meson.build
new file mode 100644
index 0000000..32baaad
--- /dev/null
+++ b/tests/meson.build
@@ -0,0 +1,40 @@
+gtest_dep = dependency('gtest', main: true, disabler: true, required: false)
+gmock_dep = dependency('gmock', disabler: true, required: false)
+if not gtest_dep.found() or not gmock_dep.found()
+    gtest_proj = import('cmake').subproject('googletest', required: false)
+    if gtest_proj.found()
+        gtest_dep = declare_dependency(
+            dependencies: [
+                dependency('threads'),
+                gtest_proj.dependency('gtest'),
+                gtest_proj.dependency('gtest_main'),
+            ]
+        )
+        gmock_dep = gtest_proj.dependency('gmock')
+  else
+        assert(
+            not get_option('tests').enabled(),
+            'Googletest is required if tests are enabled'
+        )
+  endif
+endif
+
+test(
+    'telemetry-ut',
+    executable(
+        'telemetry-ut',
+        [
+            '../src/persistent_json_storage.cpp',
+            'src/test_persistent_json_storage.cpp',
+        ],
+        dependencies: [
+            boost,
+            gmock_dep,
+            gtest_dep,
+            nlohmann_json,
+            phosphor_logging,
+            sdbusplus,
+        ],
+        include_directories: '../src',
+    )
+)