Added version number to pystencils

Pystencils should have a __version__ attribute

pystencils/__init__.py

 """Module to generate stencil kernels in C or CUDA using sympy expressions and call them as Python functions"""
-import os.path
 from . import sympy_gmpy_bug_workaround  # NOQA
 from . import fd
 from . import stencil as stencil
@@ -22,10 +21,13 @@ try:
 except ImportError:
     pass
 
+def get_file_path():
+    import os.path
+    file_path = os.path.abspath(os.path.dirname(__file__))
+    return os.path.join(file_path, '../RELEASE-VERSION')
+
 try:
-    my_path = os.path.abspath(os.path.dirname(__file__))
-    path = os.path.join(my_path, '../RELEASE-VERSION')
-    __version__ = open(path, 'r').read()
+    __version__ = open(get_file_path(), 'r').read()
 except IOError:
     __version__ = 'Please install pystencils with setup.py'