per cabal warnings, default-language

PaymentServer.cabal

@@ -64,16 +64,17 @@ executable PaymentServer-generate-key
   default-language:    Haskell2010
 
 test-suite PaymentServer-tests
-  type:            exitcode-stdio-1.0
-  hs-source-dirs:  test
-  main-is:         Spec.hs
-  other-modules:   Persistence
-  build-depends:   base
-                 , text
-                 , tasty
-                 , tasty-hunit
-                 , directory
-                 , PaymentServer
+  type:                exitcode-stdio-1.0
+  hs-source-dirs:      test
+  main-is:             Spec.hs
+  other-modules:       Persistence
+  build-depends:       base
+                     , text
+                     , tasty
+                     , tasty-hunit
+                     , directory
+                     , PaymentServer
+  default-language: Haskell2010
 
 source-repository head
   type:     git