[BUG] Secure variables only for own repositories/PRs

[guibranco]

Description

When the build runs from a forked repository, it fails when it needs to use a secure environment variable.
Conditionally execute these steps only if not in a forked pull request.

Screenshots

- ps: if(-Not $env:FORKED_DETECTION) {
    // Execute the action
    codeclimate-test-reporter upload-coverage -i "Tests\%SOLUTION_NAME%.UnitTests\code-climate.json" -r %CODECLIMATE_TOKEN% 
}

Additional information

Maybe we can use the APPVEYOR_PULL_REQUEST_HEAD_REPO_NAME environment variable to detect the repository where the PR comes from