Support netstandard1.3+

Author: ghost1face

src/FileTypeInterrogator.Tests/FileTypeInterrogator.Tests.csproj

@@ -10,7 +10,7 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>FileTypeInterrogator.Tests</RootNamespace>
     <AssemblyName>FileTypeInterrogator.Tests</AssemblyName>
-    <TargetFrameworkVersion>v4.6.1</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.6</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <ProjectTypeGuids>{3AC096D0-A1C2-E12C-1390-A8335801FDAB};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>
     <VisualStudioVersion Condition="'$(VisualStudioVersion)' == ''">15.0</VisualStudioVersion>

src/FileTypeInterrogator/BaseFileTypeInterrogator.cs

@@ -273,7 +273,7 @@ private bool IsUTF8(byte[] input, out bool hasBOM)
                 UTF8Encoding utf8WithoutBOM = new UTF8Encoding(false, true);
                 try
                 {
-                    utf8WithoutBOM.GetString(input);
+                    utf8WithoutBOM.GetString(input, 0, input.Length);
                     isUTF8 = true;
                 }
                 catch (ArgumentException)

src/FileTypeInterrogator/FileTypeInterrogator.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>netstandard1.4;netstandard2.0</TargetFrameworks>
+    <TargetFrameworks>netstandard1.3;</TargetFrameworks>
     <PackageProjectUrl>https://github.com/ghost1face/FileTypeInterrogator</PackageProjectUrl>
     <RepositoryUrl>https://github.com/ghost1face/FileTypeInterrogator</RepositoryUrl>
     <PackageTags>file-type-detection file-types magic-numbers content-type mime-type</PackageTags>