default RV naming

[rcabanasdepaz]

The first RV created is called "randvar_0_2", shouldn't it be "randvar_0"?

Python 3.6.0 (v3.6.0:41df79263a11, Dec 22 2016, 17:23:13) 
Type 'copyright', 'credits' or 'license' for more information
IPython 7.5.0 -- An enhanced Interactive Python. Type '?' for help.
PyDev console: using IPython 7.5.0

Python 3.6.0 (v3.6.0:41df79263a11, Dec 22 2016, 17:23:13) 
[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin

In[2]: import inferpy as inf
In[3]: x = inf.Normal(loc = 0, scale = 1)
In[4]: x
Out[4]: <inf.RandomVariable (Normal distribution) named randvar_0_2/, shape=(), dtype=float32>