Update installation command

README.md

@@ -12,7 +12,8 @@ The least-squares solver uses Björck's corrected semi-normal equation (CSNE) ap
 ## Installing
 
 ```julia
-Pkg.add(url="https://github.com/mpf/QRupdate.jl")
+import Pkg
+Pkg.add("QRupdate")
 ```
 
 ## Examples
@@ -86,4 +87,4 @@ x, r = csne(R, A, b)
 - 19 Oct 2007: Sparse `A`, a makes `c` and `u` sparse. Force them to be dense.
 - 04 Aug 2008: Update `u` using `du`, rather than `u = R*z` as in Ake's book.  We guess that it might be slightly more accurate, but it's hard to tell.  No `R*z` makes it a little cheaper.
 - 03 Sep 2008: Generalize `A` to be `[A; β*I]` for some scalar `β`.  Update `u` using `du`, but keep Ake's version in comments.
-- 29 Dec 2015: Converted to Julia.
+- 29 Dec 2015: Converted to Julia.