updated tests to vs 2015 and fix warning

tests/logs/.gitignore

-*.txt
-*.log

tests/tests.vcxproj

@@ -26,7 +26,7 @@
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <UseDebugLibraries>true</UseDebugLibraries>
-    <PlatformToolset>v120</PlatformToolset>
+    <PlatformToolset>v140</PlatformToolset>
     <CharacterSet>MultiByte</CharacterSet>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'" Label="Configuration">
@@ -38,7 +38,7 @@
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <UseDebugLibraries>false</UseDebugLibraries>
-    <PlatformToolset>v120</PlatformToolset>
+    <PlatformToolset>v140</PlatformToolset>
     <WholeProgramOptimization>true</WholeProgramOptimization>
     <CharacterSet>MultiByte</CharacterSet>
   </PropertyGroup>

tests/utils.cpp

@@ -41,5 +41,5 @@ std::size_t get_filesize(const std::string& filename)
     if (!ifs)
         throw std::runtime_error("Failed open file ");
 
-    return ifs.tellg();
+    return static_cast<std::size_t>(ifs.tellg());
 }