pylightning: allow version querying from within modules.

With the preceeding UTF-8 fix, I'd like to detect UTF-8 support.  But
AFAICT Python doesn't have a standard way of doing version exposure.

So I added __version__, but now we need to make sure it matches.  I
used the hackiest possible method.

[ Christian Decker fixed version to be sane, so previous comment no longer
  applies! --RR ]
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

contrib/pylightning/setup.py

@@ -1,10 +1,12 @@
 from setuptools import setup
+import lightning
+
 
 with open('README.md', encoding='utf-8') as f:
     long_description = f.read()
 
 setup(name='pylightning',
-      version='0.0.7',
+      version=lightning.__version__,
       description='Client library for lightningd',
       long_description=long_description,
       long_description_content_type='text/markdown',