Unnecessary dependency on PS5

[peppekerstens]

Documentation requirements says PowerShell 3
https://github.com/Azure/NetworkMonitoring/blob/master/AzureCT/PerformanceTesting.md#prerequisites

The module has requirement for PS5:

NetworkMonitoring/AzureCT/PowerShell/AzureCT/AzureCT.psd1

Line 34 in c38a547

PowerShellVersion = '5.0'

Removed the line in the psd, works fine under 4.0...

Please remove psd requirement or lower to 3.0/4.0