New arora2013 solver

Author: Jorge M.G

README.md

@@ -33,7 +33,7 @@ print([solver.__name__ for solver in ALL_SOLVERS])
 At this moment, the following algorithms are available:
 
 ```bash
->>> ['gooding1990', 'izzo2015']
+>>> ['gooding1990', 'arora2015', 'izzo2015']
 ```
 
 ## How can I use a solver?

src/lamberthub/__init__.py

@@ -1,14 +1,15 @@
 """ A collection of Lambert's problem solvers """
 
+from lamberthub.universal_solvers.arora import arora2013
 from lamberthub.universal_solvers.gooding import gooding1990
 from lamberthub.universal_solvers.izzo import izzo2015
 
 __version__ = "0.1.dev0"
 
-ALL_SOLVERS = [gooding1990, izzo2015]
+ALL_SOLVERS = [gooding1990, arora2013, izzo2015]
 """ A list holding all lamberthub available solvers """
 
-ZERO_REV_SOLVERS = [gooding1990, izzo2015]
+ZERO_REV_SOLVERS = [gooding1990, arora2013, izzo2015]
 """ A list holding all direct-revolution lamberthub solvers """
 
 MULTI_REV_SOLVERS = [gooding1990, izzo2015]