treewide: fix invocations of installBin command

I've removed the trivial command in 4e72b61de.
I think `install -Dt "$out/bin"` is a better replacement anyway,
as it can be easily used to other directories than $out/bin.

/cc @ehmry who seems to maintain many packages with this usage.
(BTW, it would be better to have maintainer attribute same as github
username, as it makes pinging maintainers much easier.)

pkgs/development/compilers/nim/default.nix

@@ -13,7 +13,7 @@ stdenv.mkDerivation rec {
   buildPhase   = "sh build.sh";
   installPhase =
     ''
-      installBin bin/nim
+      install -Dt "$out/bin" bin/nim
       substituteInPlace install.sh --replace '$1/nim' "$out"
       sh install.sh $out
     '';