Adds cervix to symptoms:

has 3 properties: opening, firmness and position (which is optional);

components/cycle-day/labels/labels.js

@@ -2,10 +2,16 @@ const bleeding = ['spotting', 'light', 'medium', 'heavy']
 const mucusFeeling = ['dry', 'nothing', 'wet', 'slippery']
 const mucusTexture = ['nothing', 'creamy', 'egg white']
 const mucusNFP = ['t', 'Ø', 'f', 'S', '+S']
+const cervixOpening = ['closed', 'medium', 'open']
+const cervixFirmness = ['hard', 'soft']
+const cervixPosition = ['low', 'medium', 'high']
 
 export {
   bleeding,
   mucusFeeling,
   mucusTexture,
-  mucusNFP
+  mucusNFP,
+  cervixOpening,
+  cervixFirmness,
+  cervixPosition
 }