use dev Pkg version

Author: IanButterworth

stdlib/Pkg.version

@@ -1,4 +1,4 @@
-PKG_BRANCH = master
-PKG_SHA1 = 482399a51bc8bea0c58cb8722fd7ddf7637aff77
-PKG_GIT_URL := https://github.com/JuliaLang/Pkg.jl.git
-PKG_TAR_URL = https://api.github.com/repos/JuliaLang/Pkg.jl/tarball/$1
+PKG_BRANCH = ib/test_filtering
+PKG_SHA1 = a340db063c18648a5630f3f2155af7cd1d2a4515
+PKG_GIT_URL := https://github.com/IanButterworth/Pkg.jl.git
+PKG_TAR_URL = https://api.github.com/repos/IanButterworth/Pkg.jl/tarball/$1