Fixed .gitlab-ci-simple.yml

.gitlab-ci-simple.yml

-
 # see https://hub.docker.com/repository/docker/konttipoju/tinytex
 image: konttipoju/tinytex:2019-12g
 
@@ -10,6 +9,7 @@ stages:
 # build latex/thesis.tex -> latex/thesis.pdf using pdflatex
 # shell-escape functionality is required by the minted package
 build:
+  stage: build
   script:
     - cd latex
     - latexmk -pdf --shell-escape thesis.tex
@@ -19,5 +19,6 @@ artifacts:
 
 # a validation prints "PASS + something" is the file is PDF/A conformant
 validate:
+  stage: validate
   script:
     - pdfa-validate latex/thesis.pdf|grep '^PASS'