Bump version to 0.4.0

Update README and add license headers to optimisation code

README.md

@@ -114,6 +114,14 @@ References
 Versions
 --------
 
+0.4.0  10th November 2019
+  - Add optimisation with Differential Evolution
+  - More unit testing, documentation
+
+0.3.0  28th July 2019
+  - Add 4th-order solver for potential
+  - Add convergence test
+
 0.2.0  12th March 2019
   - Add field line tracer, `freegs.fieldtracer`
   - Add Equilibrium.Btor toroidal field calculation

freegs/__init__.py

@@ -28,7 +28,7 @@
 
 """
 
-__version__ = "0.3.0"
+__version__ = "0.4.0"
 
 from .equilibrium import Equilibrium
 

freegs/optimise.py

@@ -1,7 +1,25 @@
-#
-# Routines for optimising equilibria
-# These make use of the generic "optimiser" routines
-#
+"""
+Routines for optimising equilibria
+These make use of the generic "optimiser" routines
+
+Copyright 2019 Ben Dudson, University of York. Email: benjamin.dudson@york.ac.uk
+
+This file is part of FreeGS.
+
+FreeGS is free software: you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+FreeGS is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License
+along with FreeGS.  If not, see <http://www.gnu.org/licenses/>.
+
+"""
 
 from . import optimiser
 from . import polygons

freegs/optimiser.py

@@ -1,13 +1,28 @@
-# 
-# Differential Evolution optimisation
-#
-# Implemented generically, to optimise opaque objects
-#
-# The optimiser copies objects using deepcopy, and manipulates objects
-# using supplied control objects.
-#
-# 
-#
+""" 
+Differential Evolution optimisation
+
+Implemented generically, to optimise opaque objects
+
+The optimiser copies objects using deepcopy, and manipulates objects
+using supplied control objects.
+
+Copyright 2019 Ben Dudson, University of York. Email: benjamin.dudson@york.ac.uk
+
+This file is part of FreeGS.
+
+FreeGS is free software: you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+FreeGS is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License
+along with FreeGS.  If not, see <http://www.gnu.org/licenses/>.
+"""
 
 import random
 import copy