Exclude by assembly level System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage

[MarcoRossignoli]

closes #290

cc: @tonerdo @SefaOray @petli @zmhh @olivier-spinelli @bhales42

[MarcoRossignoli]

Manual test
No attribute

F:\git\coverletissues\testpr589
λ dotnet test /p:CollectCoverage=true /bl
C:\Program Files\dotnet\sdk\3.0.100\MSBuild.dll -nologo -distributedlogger:Microsoft.DotNet.Tools.MSBuild.MSBuildLogger,C:\Program Files\dotnet\sdk\3.0.100\dotnet.dll*Microsoft.DotNet.Tools.MSBuild.MSBuildForwardingLogger,C:\Program Files\dotnet\sdk\3.0.100\dotnet.dll -maxcpucount -nodereuse:false -restore -target:VSTest -verbosity:m -verbosity:quiet /bl /p:CollectCoverage=true .\testpr589.sln
Test run for F:\git\coverletissues\testpr589\bin\Debug\netcoreapp3.0\testpr589.dll(.NETCoreApp,Version=v3.0)
Microsoft (R) Test Execution Command Line Tool Version 16.3.0
Copyright (c) Microsoft Corporation.  All rights reserved.

Starting test execution, please wait...

A total of 1 test files matched the specified pattern.

Test Run Successful.
Total tests: 1
     Passed: 1
 Total time: 1,1008 Seconds

Calculating coverage result...
  Generating report 'F:\git\coverletissues\testpr589\coverage.json'

+---------------+------+--------+--------+
| Module        | Line | Branch | Method |
+---------------+------+--------+--------+
| ClassLibrary1 | 100% | 100%   | 100%   |
+---------------+------+--------+--------+
| ClassLibrary2 | 100% | 100%   | 100%   |
+---------------+------+--------+--------+

+---------+------+--------+--------+
|         | Line | Branch | Method |
+---------+------+--------+--------+
| Total   | 100% | 100%   | 100%   |
+---------+------+--------+--------+
| Average | 100% | 100%   | 100%   |
+---------+------+--------+--------+

With attribute [assembly: ExcludeFromCodeCoverage] on ClassLibrary2

F:\git\coverletissues\testpr589
λ dotnet test /p:CollectCoverage=true /bl
C:\Program Files\dotnet\sdk\3.0.100\MSBuild.dll -nologo -distributedlogger:Microsoft.DotNet.Tools.MSBuild.MSBuildLogger,C:\Program Files\dotnet\sdk\3.0.100\dotnet.dll*Microsoft.DotNet.Tools.MSBuild.MSBuildForwardingLogger,C:\Program Files\dotnet\sdk\3.0.100\dotnet.dll -maxcpucount -nodereuse:false -restore -target:VSTest -verbosity:m -verbosity:quiet /bl /p:CollectCoverage=true .\testpr589.sln
Test run for F:\git\coverletissues\testpr589\bin\Debug\netcoreapp3.0\testpr589.dll(.NETCoreApp,Version=v3.0)
Microsoft (R) Test Execution Command Line Tool Version 16.3.0
Copyright (c) Microsoft Corporation.  All rights reserved.

Starting test execution, please wait...

A total of 1 test files matched the specified pattern.

Test Run Successful.
Total tests: 1
     Passed: 1
 Total time: 1,0850 Seconds

Calculating coverage result...
  Generating report 'F:\git\coverletissues\testpr589\coverage.json'

+---------------+------+--------+--------+
| Module        | Line | Branch | Method |
+---------------+------+--------+--------+
| ClassLibrary1 | 100% | 100%   | 100%   |
+---------------+------+--------+--------+

+---------+------+--------+--------+
|         | Line | Branch | Method |
+---------+------+--------+--------+
| Total   | 100% | 100%   | 100%   |
+---------+------+--------+--------+
| Average | 100% | 100%   | 100%   |
+---------+------+--------+--------+