Introduce initial Amarisoft ENB support

* object class expects the amarisoft software to be placed in directory
  provided by env var AMARISOFT_PATH_ENB. On local runs, it will run the
  software from there. On remote runs it will copy over that directory to
  the slave.
* Configuration provided works with 6 PRBs, but probably won't work for
  other values (yet).
* ZMQ support not yet available, only UHD.

One can select the Amarisoft ENB by declaring it in resources.conf:
"""
- label: AmarisoftENB-B200
  type: amarisoftenb
  rf_dev_type: uhd
  rf_dev_args: "type=b200,serial=317B9FE,recv_frame_size=9232,send_frame_size=9232"
  remote_user: jenkins
  addr: 10.12.1.206
"""

And running:
"""
$ export AMARISOFT_PATH_ENB=/path/to/binaries
$ osmo-gsm-tester.py ... -s 4g:amarisoftenb-rftype@uhd+srsue-rftype@UHD+mod-enb-nprb@6 -t ping
"""

Change-Id: I1ddf4962ea6438ad977382ab201b724028ca46b3
diff --git a/src/osmo_gsm_tester/resource.py b/src/osmo_gsm_tester/resource.py
index bb44f39..d14ee96 100644
--- a/src/osmo_gsm_tester/resource.py
+++ b/src/osmo_gsm_tester/resource.py
@@ -29,7 +29,7 @@
 from . import bts_sysmo, bts_osmotrx, bts_osmovirtual, bts_octphy, bts_nanobts, bts_oc2g
 from . import modem
 from . import ms_osmo_mobile
-from . import srs_ue, srs_enb
+from . import srs_ue, srs_enb, amarisoft_enb
 
 from .util import is_dict, is_list
 
@@ -140,6 +140,7 @@
 
 KNOWN_ENB_TYPES = {
         'srsenb': srs_enb.srsENB,
+        'amarisoftenb': amarisoft_enb.AmarisoftENB,
 }
 
 KNOWN_MS_TYPES = {