Rename python2 debian package to python-ligo-lvalert

This merge renames the python2 package for debian to python-ligo-lw; this follows the convention for debian package naming.

debian/control

@@ -12,7 +12,7 @@ Standards-Version: 3.8.4
 X-Python-Version: >=2.7
 X-Python3-Version: >=3.4
 
-Package: python2-ligo-lvalert
+Package: python-ligo-lvalert
 Architecture: all
 Depends: ${misc:Depends}, ${python:Depends}, python-pyxmpp, python-libxml2, python-m2crypto, python-dnspython, python-ligo-common, python-sleekxmpp
 Provides: ${python:Provides}