fixed clang-tidy errors

fixed clang compilation error and few clang-tidy issues

Tested:
- Code compiles, all unit tests are passing
- Number of reported clang-tidy issues decreased

Change-Id: Ie3f88db6e2dffb26ec6c56dbdc1ce5bad288dccd
Signed-off-by: Krzysztof Grobelny <krzysztof.grobelny@intel.com>
diff --git a/tests/src/mocks/trigger_mock.hpp b/tests/src/mocks/trigger_mock.hpp
index be40a65..cd0e5f4 100644
--- a/tests/src/mocks/trigger_mock.hpp
+++ b/tests/src/mocks/trigger_mock.hpp
@@ -7,7 +7,7 @@
 class TriggerMock : public interfaces::Trigger
 {
   public:
-    TriggerMock(std::string id)
+    explicit TriggerMock(std::string id)
     {
         using namespace testing;