CI: updated requirements

requirements/build.txt

@@ -1,2 +1,4 @@
+pytest
+
 matplotlib
 Pillow

requirements/coverage.txt

@@ -0,0 +1,11 @@
+# Testing
+pytest
+pytest-cov
+
+# Package requirements
+pandas
+jinja2
+
+# Optional
+matplotlib
+Pillow

requirements/docs.txt

@@ -1,2 +1,3 @@
-sphinx_rtd_theme
-sphinx >= 1.7.5
+sphinx >= 1.7.5
+pydata-sphinx-theme
+sphinx_rtd_theme