add Office xml test for latex free fields (#3680)

src/test/resources/org/jabref/logic/exporter/MsBibExportFormatTestLatexFree.bib

@@ -0,0 +1,12 @@
+% Encoding: UTF-8
+
+@InProceedings{Grossmann_2005,
+  author    = {M. Grossmann and M. Bauer and N. Honle and U.-P. Kappeler and D. Nicklas and T. Schwarz},
+  title     = {Efficiently Managing Context Information for Large-Scale Scenarios},
+  booktitle = {Third {IEEE} International Conference on Pervasive Computing and Communications},
+  publisher = {{IEEE}},
+  doi       = {10.1109/percom.2005.17},
+  timestamp = {2018-01-31},
+}
+
+@Comment{jabref-meta: databaseType:biblatex;}

src/test/resources/org/jabref/logic/exporter/MsBibExportFormatTestLatexFree.xml

@@ -0,0 +1,43 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<b:Sources xmlns:b="http://schemas.openxmlformats.org/officeDocument/2006/bibliography" xmlns="http://schemas.openxmlformats.org/officeDocument/2006/bibliography" SelectedStyle="">
+<b:Source>
+<b:BIBTEX_Entry>inproceedings</b:BIBTEX_Entry>
+<b:SourceType>ConferenceProceedings</b:SourceType>
+<b:Title>Efficiently Managing Context Information for Large-Scale Scenarios</b:Title>
+<b:Tag>Grossmann_2005</b:Tag>
+<b:Publisher>IEEE</b:Publisher>
+<b:BookTitle>Third IEEE International Conference on Pervasive Computing and Communications</b:BookTitle>
+<b:DOI>10.1109/percom.2005.17</b:DOI>
+<b:Author>
+<b:Author>
+<b:NameList>
+<b:Person>
+<b:Last>Grossmann</b:Last>
+<b:First>M.</b:First>
+</b:Person>
+<b:Person>
+<b:Last>Bauer</b:Last>
+<b:First>M.</b:First>
+</b:Person>
+<b:Person>
+<b:Last>Honle</b:Last>
+<b:First>N.</b:First>
+</b:Person>
+<b:Person>
+<b:Last>Kappeler</b:Last>
+<b:First>U.-P.</b:First>
+</b:Person>
+<b:Person>
+<b:Last>Nicklas</b:Last>
+<b:First>D.</b:First>
+</b:Person>
+<b:Person>
+<b:Last>Schwarz</b:Last>
+<b:First>T.</b:First>
+</b:Person>
+</b:NameList>
+</b:Author>
+</b:Author>
+<b:ConferenceName>Third IEEE International Conference on Pervasive Computing and Communications</b:ConferenceName>
+</b:Source>
+</b:Sources>