requirements: added missing lscsoft-glue

requirements.txt

@@ -19,6 +19,7 @@ ipython==5.5.0
 git+https://git.ligo.org/lscsoft/lvalert.git@13a9e40649eeb2a14369fcee950cd49154f195ad#egg=ligo-lvalert
 #ligo-lvalert==1.5.5
 ligo-lvalert-overseer==0.1.3
+lscsoft-glue==1.60.0
 lxml==4.2.0
 matplotlib==2.0.0
 mock==2.0.0