treewide: add final newline

pkgs/development/tools/misc/mdl/gemset.nix

@@ -94,4 +94,4 @@
     };
     version = "2.0.0";
   };
-}
+}

pkgs/development/tools/misc/one_gadget/gemset.nix

@@ -31,4 +31,4 @@
     };
     version = "1.7.2";
   };
-}
+}

pkgs/development/tools/misc/travis/gemset.nix

@@ -266,4 +266,4 @@
     };
     version = "1.2.8";
   };
-}
+}

pkgs/development/tools/misc/watson-ruby/gemset.nix

@@ -15,4 +15,4 @@
     };
     version = "1.6.3";
   };
-}
+}