Use five-digit dev build suffixes

Author: nblumhardt

Build.ps1

@@ -5,7 +5,7 @@ if(Test-Path .\artifacts) { Remove-Item .\artifacts -Force -Recurse }
 & dotnet restore --no-cache
 
 $branch = @{ $true = $env:APPVEYOR_REPO_BRANCH; $false = $(git symbolic-ref --short -q HEAD) }[$env:APPVEYOR_REPO_BRANCH -ne $NULL];
-$revision = @{ $true = $env:APPVEYOR_BUILD_NUMBER; $false = "local" }[$env:APPVEYOR_BUILD_NUMBER -ne $NULL];
+$revision = @{ $true = "{0:00000}" -f [convert]::ToInt32("0" + $env:APPVEYOR_BUILD_NUMBER, 10); $false = "local" }[$env:APPVEYOR_BUILD_NUMBER -ne $NULL];
 $suffix = @{ $true = ""; $false = "$branch-$revision"}[$branch -eq "master" -and $revision -ne "local"]
 
 foreach ($src in ls src/Serilog.*) {