conditionally execute RNN tests

.gitlab-ci.yml

@@ -1,3 +1,6 @@
+before_script:
+  - export CI_CURNN_TEST=true
+
 variables:
   CI_IMAGE_TAG: 'cuda'
 

test/cuda/cuda.jl

@@ -41,5 +41,7 @@ end
 if CuArrays.libcudnn != nothing
     @info "Testing Flux/CUDNN"
     include("cudnn.jl")
-    # include("curnn.jl")
+    if !haskey(ENV, "CI_CURNN_TEST")
+      include("curnn.jl")
+    end
 end