Update requirements.txt

requirements.txt

@@ -15,18 +15,17 @@ elasticsearch>=6.3.1,<7.0.0
 elasticsearch-dsl>=6.3.1,<7.0.0
 kafka-python>=1.4.4
 mailsuite>=1.1.0
-nose
-pygments
-flake8
-doc8
-collective.checkdocs
-jinja2
-packaging
-imagesize
-alabaster
-babel
+nose>=1.3.7
+flake8>=3.7.8
+doc8>=0.8.0
+collective.checkdocs>=0.2
+jinja2>=2.10.1
+packaging>=19.1
+imagesize>=1.1.0
+alabaster>=0.7.12
+Babel>=2.7.0
 rstcheck>=3.3.1
-sphinx
-sphinx_rtd_theme
-wheel
-codecov
+sphinx>=1.0.5
+sphinx_rtd_theme>=0.4.3
+wheel>=0.33.6
+codecov>=2.0.15