coverage pin test part deux (#3908)

* we pinned coverage for xml generation...let's try everywhere

* add so many comments
diff --git a/.travis/install.sh b/.travis/install.sh
index e65030f..6090e07 100755
--- a/.travis/install.sh
+++ b/.travis/install.sh
@@ -78,4 +78,5 @@
 
 python -m virtualenv ~/.venv
 source ~/.venv/bin/activate
+# This coverage pin must be kept in sync with tox.ini
 pip install tox codecov coverage==4.3.4
diff --git a/Jenkinsfile b/Jenkinsfile
index b79a407..93819ab 100644
--- a/Jenkinsfile
+++ b/Jenkinsfile
@@ -246,6 +246,7 @@
                             IF %ERRORLEVEL% NEQ 0 EXIT /B %ERRORLEVEL%
                             virtualenv .codecov
                             call .codecov/Scripts/activate
+                            REM this pin must be kept in sync with tox.ini
                             pip install coverage==4.3.4
                             pip install codecov
                             codecov -e JOB_BASE_NAME,LABEL,TOXENV
@@ -264,6 +265,7 @@
                                     tox -r --  --color=yes
                                 virtualenv .venv
                                 source .venv/bin/activate
+                                # This pin must be kept in sync with tox.ini
                                 pip install coverage==4.3.4
                                 bash <(curl -s https://codecov.io/bash) -e JOB_BASE_NAME,LABEL,TOXENV
                             """
@@ -283,6 +285,7 @@
                                 fi
                                 virtualenv .venv
                                 source .venv/bin/activate
+                                # This pin must be kept in sync with tox.ini
                                 pip install coverage==4.3.4
                                 bash <(curl -s https://codecov.io/bash) -e JOB_BASE_NAME,LABEL,TOXENV,IMAGE_NAME
                             """
diff --git a/tox.ini b/tox.ini
index 777e9b8..51d81d2 100644
--- a/tox.ini
+++ b/tox.ini
@@ -6,7 +6,8 @@
 extras =
    test
 deps =
-    coverage
+    # This must be kept in sync with Jenkinsfile and .travis/install.sh
+    coverage==4.3.4
     ./vectors
 passenv = ARCHFLAGS LDFLAGS CFLAGS INCLUDE LIB LD_LIBRARY_PATH USERNAME
 commands =