update test=develop (#2416)

add CUDAContext assignment operator to fix cuda compile bug

lite/core/context.h

@@ -232,6 +232,13 @@ class Context<TargetType::kCUDA> {
 
   std::string name() const { return "CUDAContext"; }
 
+  CUDAContext& operator=(const CUDAContext& context) {
+    this->Init(
+        context.device_id_, context.exec_stream_id_, context.io_stream_id_);
+    cublas_fp32_ = const_cast<CUDAContext&>(context).cublas_fp32();
+    return *this;
+  }
+
  private:
   int device_id_;
   // overall information