.gitlab-ci.yml: add required dependencies for pyBigWig

.gitlab-ci.yml

@@ -2,8 +2,10 @@ image: "python:3.8-slim"
 
 before_script:
   - apt-get update
-  - apt-get install -y libcurl-dev
+  - apt-get install build-essential
+  - apt-get install -y libcurl4-gnutls-dev
   - apt-get install -y zlib1g
+  - apt-get install -y zlib1g-dev
   - pip install coverage
   - pip install matplotlib==3.1.2
   - pip install pandas==1.0.3