Code for tables is only loaded when tables are in the document.

.travis.yml

@@ -4,7 +4,7 @@ language: r
 pandoc_version: 1.19.2.1
 install:
   - sudo apt-get install poppler-utils 
-  - tlmgr install xecjk filehook unicode-math ucharcat pagecolor babel-german ly1 mweights sourcecodepro sourcesanspro 
+  - tlmgr install longtable xecjk filehook unicode-math ucharcat pagecolor babel-german ly1 mweights sourcecodepro sourcesanspro 
 before_script:
   - cd examples
 script:

eisvogel.latex

@@ -413,7 +413,7 @@ $endif$
 %
 % tables
 %
-\usepackage{booktabs} % needed for midrule
+$if(tables)$
 \usepackage{tabularx}
 \renewcommand{\arraystretch}{1.6} % table spacing
 
@@ -426,6 +426,7 @@ $endif$
 \let\endoldlongtable\endlongtable
 \renewenvironment{longtable}{\rowcolors{2}{white}{table-gray}\oldlongtable} {
 \endoldlongtable}
+$endif$
 
 %
 % remove paragraph indention