Test initial size of StaticJsonB

tests/StaticJsonBufferTests.cpp

@@ -1,8 +1,14 @@
 #include <gtest/gtest.h>
 #include <StaticJsonBuffer.h>
 
-TEST(StaticJsonBufferTests, CapacityMatchTemplateParameter)
+TEST(StaticJsonBuffer, CapacityMatchTemplateParameter)
 {
     StaticJsonBuffer<42> json;   
     EXPECT_EQ(42, json.capacity());
+}
+
+TEST(StaticJsonBuffer, InitialSizeIsZero)
+{
+    StaticJsonBuffer<42> json;
+    EXPECT_EQ(0, json.size());
 }