Use env var to evaluate nf-test workDir

Author: drpatelh

nf-test.config

@@ -3,7 +3,7 @@ config {
     testsDir "."
 
     // nf-test directory used to create temporary files for each test
-    workDir "nf-test"
+    workDir System.getenv("NFT_WORKDIR") ?: ".nf-test"
 
     // Location of an optional nextflow.config file specific for executing pipeline tests
     configFile "tests/nextflow.config"