Exclude DBTest.FileCreationRandomFailure as a long running test

Increase concurrency to 18
  Fix exclusion but in the ps script

appveyor.yml

@@ -10,6 +10,6 @@ build:
   verbosity: minimal
 test:
 test_script:
-- ps: build_tools\run_ci_db_test.ps1 -EnableRerun -Run db_test -Exclude DBTest.Randomized -Concurrency 16
+- ps: build_tools\run_ci_db_test.ps1 -EnableRerun -Run db_test -Exclude DBTest.Randomized,DBTest.FileCreationRandomFailure -Concurrency 18
 - ps: build_tools\run_ci_db_test.ps1 -Run env_test -Concurrency 1
 

build_tools/run_ci_db_test.ps1

@@ -126,7 +126,7 @@ function Normalize-DbTests($HashTable) {
 function MakeAndAdd([string]$token, $HashTable) {
     $test_name = $token -replace '.exe$', ''
     $log_name =  -join ($test_name, ".log")
-    if(!$ExcludeTests.Contains($test)) {
+    if(!$ExcludeTests.Contains($test_name)) {
         $HashTable.Add($test_name, $log_name)
     } else {
         Write-Warning "Test $test_name is excluded"