Merge pull request #249 from JuliaPy/tk/tryboth

try both PyQt4 and PyQt5

Author: stevengj

src/PyPlot.jl

@@ -134,7 +134,11 @@ function find_backend(matplotlib::PyObject)
                 if defaultgui == :qt_pyside
                     pyimport_conda("PySide", "pyside")
                 else
-                    pyimport_conda("PyQt4", "pyqt")
+                    try
+                        pyimport_conda("PyQt5", "pyqt")
+                    catch
+                        pyimport("PyQt4")
+                    end
                 end
             elseif defaultgui == :wx
                 pyimport_conda("wx", "wxpython")