Update workflow

Author: DanielKotik

.github/workflows/gh-pages.yml

@@ -10,6 +10,7 @@ on:
       - master
       - develop
 
+
 jobs:
   python-style-checks:
     runs-on: ubuntu-20.04
@@ -67,7 +68,8 @@ jobs:
                                   gsfonts \
                                   latexmk \
                                   texlive \
-                                  texlive-latex-extra
+                                  texlive-latex-extra \
+                                  imagemagick
 
       - name: Generate LaTeX code to check for errors
         run: |