added versioneer for versioning

The versioneer code is kept in _version.py so that version.py can
be left alone for backwards compatibility

Author: alorenzo175

.gitattributes

@@ -0,0 +1 @@
+pvlib/version.py export-subst

MANIFEST.in

@@ -1,6 +1,8 @@
 #include *.txt
+include versioneer.py
+include pvlib/_version.py
 recursive-include pvlib/data *
 include README.md
 include pvlib/spa_c_files/*.h
 
-#recursive-include docs *.txt
+#recursive-include docs *.txt

docs/sphinx/source/whatsnew/v0.3.1.txt

@@ -10,23 +10,29 @@ We recommend that all users upgrade to this version.
 Enhancements
 ~~~~~~~~~~~~
 
+* Added versioneer to keep track of version changes instead
+  of manually updating pvlib/version.py. This will aid
+  developers because the version string includes the specific
+  git commit of the library code currently imported.
 
 
 Bug fixes
 ~~~~~~~~~
 
 * Fixes night tare issue in snlinverter. When the DC input power (p_dc)
   to an inverter is below the inversion startup power (Ps0), the model
-  should set the AC output (ac_power) to the night tare value (Pnt). 
+  should set the AC output (ac_power) to the night tare value (Pnt).
   The night tare power indicates the power consumed by the inverter to
   sense PV array voltage. The model was erroneously comparing Ps0 with
   the AC output power (ac_power), rather than the DC input power (p_dc).
 
 * Fixed the azimuth calculation of rotated PV panel in function
   pvlib.tracking.singleaxis(...) so that the results are consistent
   with PVsyst
+
 Contributors
 ~~~~~~~~~~~~
 
 * ejmiller2
 * Yudong Ma
+* Tony Lorenzo

pvlib/__init__.py

@@ -11,4 +11,4 @@
 from pvlib import tracking
 from pvlib import pvsystem
 from pvlib import spa
-from pvlib import modelchain
+from pvlib import modelchain