Clean up unused files

app/Main.hs

@@ -1,4 +0,0 @@
-module Main where
-
-main :: IO ()
-main = putStrLn "Nothing to see here, move along."

package.yaml

@@ -40,16 +40,6 @@ executables:
     dependencies:
     - mima-tools
 
-  mima-tools-exe:
-    main:                Main.hs
-    source-dirs:         app
-    ghc-options:
-    - -threaded
-    - -rtsopts
-    - -with-rtsopts=-N
-    dependencies:
-    - mima-tools
-
 tests:
   mima-tools-test:
     main:                Spec.hs