Revised method of setting version number.

gprMax/__init__.py

@@ -1,2 +1 @@
-# This is where the version number is set and read by setup.py and conf.py (for the docs)
-__version__ = '3.0.0b19'
+from gprMax._version import __version__

gprMax/__main__.py

@@ -1,7 +1,9 @@
 """gprMax.__main__: executed when gprMax directory is called as script."""
 
-from .gprMax import main
-main()
+import gprMax.gprMax
+
+if __name__ == '__main__':
+    gprMax.gprMax.main()
 
 # Code profiling
 # Time profiling