classic: don't allow page break in PublicationEntry

rendercv/themes/classic/PublicationEntry.j2.tex

@@ -5,6 +5,7 @@
 \begin{twocolentry}{
     <<entry.date_string>>
 }
+    \begin{minipage}{\linewidth}
         \textbf{<<entry.title>>}
 
         \vspace{<<design.margins.highlights_area.vertical_between_bullet_points>>}
@@ -21,6 +22,6 @@
         ((*- if entry.journal -*))
         <<entry.journal>>
         ((*- endif -*))
-    ((*- if entry.doi and entry.journal *)))((* endif -*))
-
+        ((*- if entry.doi and entry.journal *)))((* endif *))
+    \end{minipage}
 \end{twocolentry}