Closes #63 - adds git has and change time to logging output

During setup, this writes a file tupak/.version which contains the git
hash and change date. We can extend this in future to contain other
information. This is then printed when the logging is initialised.

setup.py

 #!/usr/bin/env python
 
 from distutils.core import setup
+import subprocess
+
+# Write a version file containing the git hash and info
+git_log = subprocess.check_output(['git', 'log', '-1', '--pretty=%h %ai'])
+git_diff = (subprocess.check_output(['git', 'diff', '.'])
+            + subprocess.check_output(['git', 'diff', '--cached', '.']))
+if git_diff == '':
+    status = '(CLEAN) ' + git_log
+else:
+    status = '(UNCLEAN) ' + git_log
+version_file = '.version'
+with open('tupak/' + version_file, 'w+') as f:
+    f.write(status)
 
 setup(name='tupak',
       version='0.1',
       packages=['tupak'],
       package_dir={'tupak': 'tupak'},
-      package_data={'tupak': ['noise_curves/*.txt', 'prior_files/*.txt']}
+      package_data={'tupak': ['noise_curves/*.txt', 'prior_files/*.txt',
+                              version_file]}
       )

tupak/utils.py

@@ -322,6 +322,11 @@ def setup_logger(outdir=None, label=None, log_level='info'):
         file_handler.setLevel(LEVEL)
         logger.addHandler(file_handler)
 
+    version_file = os.path.join(os.path.dirname(__file__), '.version')
+    with open(version_file, 'r') as f:
+        version = f.readline()
+    logging.info('Running tupak version: {}'.format(version))
+
 
 def get_progress_bar(module='tqdm'):
     if module in ['tqdm']: