KeyError: u'peer_fwd_rti' on Junos 15

[mirceaulinic]

Description of Issue/Question

Apparently, the peer_fwd_rti is still not widely available on all Junos >= 15 distributions.

napalm-junos version

(Paste verbatim output from pip freeze | grep napalm-junos between quotes below)

0.11.0

JunOS version

(Paste verbatim output from show version and haiku between quotes below)

15.1F7.3

Steps to Reproduce the Issue

Error Traceback

(Paste the complete traceback of the exception between quotes below)

>>> j.get_bgp_neighbors()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python2.7/dist-packages/napalm_junos/junos.py", line 577, in get_bgp_neighbors
    _get_bgp_neighbors_core(instance_neighbors)
  File "/usr/local/lib/python2.7/dist-packages/napalm_junos/junos.py", line 528, in _get_bgp_neighbors_core
    peer_fwd_rti = neighbor_details.pop('peer_fwd_rti')
KeyError: u'peer_fwd_rti

[mirceaulinic]

Solved in #193