Fetch pytest-blender dependencies (#1746)

* Fetch pytest-blender dependencies

* Fix command location

src/blenderbim/setup_pytest.py

@@ -0,0 +1,29 @@
+# BlenderBIM Add-on - OpenBIM Blender Add-on
+# Copyright (C) 2021 Nathan Hild <nathan.hild@gmail.com>
+#
+# This file is part of BlenderBIM Add-on.
+#
+# BlenderBIM Add-on is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# BlenderBIM Add-on is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with BlenderBIM Add-on.  If not, see <http://www.gnu.org/licenses/>.
+
+import subprocess
+import sys
+
+py_exec = str(sys.executable)
+# Ensure pip is installed
+subprocess.call([py_exec, "-m", "ensurepip", "--user" ])
+# Update pip
+subprocess.call([py_exec, "-m", "pip", "install", "--upgrade", "pip" ])
+# Install packages
+subprocess.call([py_exec,"-m", "pip", "install", f"--target={py_exec[:-14]}" + "lib", "pytest"])
+subprocess.call([py_exec,"-m", "pip", "install", f"--target={py_exec[:-14]}" + "lib", "pytest-blender"])