Remove outdated pkg.julialang.org links

Author: andreasnoack

README.md

@@ -4,8 +4,6 @@ Uniform interface for positive definite matrices of various structures.
 
 [![Build Status](https://travis-ci.org/JuliaStats/PDMats.jl.svg?branch=master)](https://travis-ci.org/JuliaStats/PDMats.jl)
 [![Coverage Status](https://img.shields.io/coveralls/JuliaStats/PDMats.jl.svg)](https://coveralls.io/r/JuliaStats/PDMats.jl?branch=master)
-[![PDMats](http://pkg.julialang.org/badges/PDMats_0.6.svg)](http://pkg.julialang.org/?pkg=PDMats&ver=0.6)
-[![PDMats](http://pkg.julialang.org/badges/PDMats_0.7.svg)](http://pkg.julialang.org/?pkg=PDMats&ver=0.7)
 
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