Use pyspinel package (#1678)

* Modified travis script to install pyspinel package

* Modifed node_cli.py to use spinel-cli from pyspinel package

.travis/before_install.sh

@@ -49,9 +49,11 @@ cd /tmp || die
     sudo -H pip install ipaddress || die
     sudo -H pip install scapy==2.3.2 || die
     sudo -H pip install pyserial || die
+    sudo -H pip install git+https://github.com/openthread/pyspinel || die
     pip install ipaddress || die
     pip install scapy==2.3.2 || die
     pip install pyserial || die
+    pip install git+https://github.com/openthread/pyspinel || die
 
     [ $BUILD_TARGET != pretty-check ] || {
         wget http://jaist.dl.sourceforge.net/project/astyle/astyle/astyle%202.05.1/astyle_2.05.1_linux.tar.gz || die

tests/scripts/thread-cert/node_cli.py

@@ -70,12 +70,7 @@ class otCli:
         """ Initialize an NCP simulation node. """
         if "top_builddir" in os.environ.keys():
             builddir = os.environ['top_builddir']
-            if "top_srcdir" in os.environ.keys():
-                srcdir = os.environ['top_srcdir']
-            else:
-                srcdir = os.path.dirname(os.path.realpath(__file__))
-                srcdir += "/../../.."
-            cmd = 'python %s/tools/spinel-cli/spinel-cli.py -p %s/examples/apps/ncp/ot-ncp-ftd -n' % (srcdir, builddir)
+            cmd = 'spinel-cli.py -p %s/examples/apps/ncp/ot-ncp-ftd -n' % (builddir)
         else:
             cmd = './ot-ncp-ftd'
         cmd += ' %d' % nodeid