Remove redundant Julia test

This is the equivalent to the pyplot-requirements test,
so just do one rather than 2.

tests/julia/pyplot/README.rst

@@ -1,17 +0,0 @@
-Julia - REQUIRE
----------------
-
-To specify dependencies in Julia, include a REQUIRE file that lists the names
-of packages you'd like to be installed. For example:
-
-```
-PyPlot
-IJulia
-DataFrames
-```
-
-Each one will be installed but **not** pre-compiled. If you'd like to
-pre-compile your Julia packages, consider using a ``postBuild`` file.
-
-Note that this example also specifies Python dependencies with an
-``environment.yml`` file.

tests/julia/pyplot/REQUIRE

@@ -1 +0,0 @@
-PyPlot

tests/julia/pyplot/environment.yml

@@ -1,3 +0,0 @@
-dependencies:
-  - matplotlib
-  

tests/julia/pyplot/verify

@@ -1,24 +0,0 @@
-#!/usr/bin/env julia
-using PyPlot
-
-# Make sure we are re-using the same conda python
-if ! startswith(PyCall.libpython, ENV["NB_PYTHON_PREFIX"] * "/lib")
-    println("Not re-using conda python! Using " * PyCall.libpython * " instead")
-    exit(1)
-end
-
-# We try to plot something, and see if the file saved exists
-x = linspace(0,2*pi,1000); y = sin(3*x + 4*cos(2*x))
-plot(x, y, color="red", linewidth=2.0, linestyle="--")
-savefig("graph.png")
-if isfile("graph.png")
-    exit(0)
-else
-    exit(1)
-end
-
-# We check that PyPlot is installed inside ${JULIA_DEPOT_PATH}
-if ! isdir(ENV["JULIA_DEPOT_PATH"] * "/packages/PyPlot")
-   println("PyPlot not installed under JULIA_DEPOT_PATH")
-   exit(1)
-end