Improve .cabal files

- Add build-tool-depends, so new-build can use hspec-discover
- Add mtl bounds in tutorial (and dependency on mtl-compact)
- Add extra-source-files to tutorial, so it's buildable from sdist

doc/tutorial/tutorial.cabal

@@ -13,6 +13,9 @@ tested-with:
   GHC==7.10.3
   GHC==8.0.2
   GHC==8.2.1
+extra-source-files:
+  static/index.html
+  static/ui.js
 
 library
   exposed-modules:     ApiType
@@ -42,7 +45,8 @@ library
                      , string-conversions
                      , bytestring
                      , attoparsec
-                     , mtl
+                     , mtl >=2.1 && <2.3
+                     , mtl-compat
                      , random
                      , js-jquery
                      , wai
@@ -61,6 +65,8 @@ test-suite spec
   hs-source-dirs: test
   main-is: Spec.hs
   other-modules: JavascriptSpec
+  build-tool-depends:
+    hspec-discover:hspec-discover
   build-depends: base == 4.*
                , tutorial
                , hspec

servant-client/servant-client.cabal

@@ -81,6 +81,8 @@ test-suite spec
   default-language: Haskell2010
   hs-source-dirs: test
   main-is: Spec.hs
+  build-tool-depends:
+    hspec-discover:hspec-discover
   other-modules:
       Servant.ClientSpec
     , Servant.Common.BaseUrlSpec

servant-docs/servant-docs.cabal

@@ -79,6 +79,8 @@ test-suite spec
   type: exitcode-stdio-1.0
   main-is: Spec.hs
   other-modules: Servant.DocsSpec
+  build-tool-depends:
+    hspec-discover:hspec-discover
   hs-source-dirs: test
   ghc-options: -Wall
   build-depends:

servant-foreign/servant-foreign.cabal

@@ -71,6 +71,8 @@ test-suite spec
   include-dirs:      include
   main-is:           Spec.hs
   other-modules:     Servant.ForeignSpec
+  build-tool-depends:
+    hspec-discover:hspec-discover
   build-depends:     base
                    , hspec >= 2.1.8
                    , servant

servant-server/servant-server.cabal

@@ -125,6 +125,8 @@ test-suite spec
       Servant.Server.UsingContextSpec.TestCombinators
       Servant.ServerSpec
       Servant.Utils.StaticFilesSpec
+  build-tool-depends:
+    hspec-discover:hspec-discover
   build-depends:
       base == 4.*
     , base-compat

servant/servant.cabal

@@ -122,6 +122,8 @@ test-suite spec
       Servant.API.ResponseHeadersSpec
       Servant.Utils.LinksSpec
       Servant.Utils.EnterSpec
+  build-tool-depends:
+    hspec-discover:hspec-discover
   build-depends:
       base == 4.*
     , base-compat