Packages build.log has moved breaking install_dependencies.jl

[KristofferC]

In order to reduce the writes to the package directory, the build.log file was moved to scratch space:

https://github.com/JuliaLang/Pkg.jl/blob/aa8b07246c66d0c694777a88100c1ec1b38d121e/src/Operations.jl#L908-L925

This means that the code:

IPython.jl/test/install_dependencies.jl

Lines 27 to 30 in c00efd5

	@info "PyCall/deps/build.log:"
	print(read(
	joinpath(dirname(dirname(pathof(IPython.PyCall))), "deps", "build.log"),
	String))

doesn't work anymore since it is trying to read a non-existing file and errors.

[vtjnash]

bump