DOC: Fix doc environment variable

Needs a hyphen

Author: TomAugspurger

.travis.yml

@@ -16,14 +16,10 @@ cache:
 
 env:
   global:
-
-  # pandas-docs/pandas-docs-travis GH #
-  #
-  # create a github personal access token
-  # cd pandas-dev/pandas
-  # travis encrypt PANDAS_GH_TOKEN=personal_access_token
-  # correct the repo to be pandas-dev/pandas, not your fork
-  secure: "EkWLZhbrp/mXJOx38CHjs7BnjXafsqHtwxPQrqWy457VDFWhIY1DMnIR/lOWG+a20Qv52sCsFtiZEmMfUjf0pLGXOqurdxbYBGJ7/ikFLk9yV2rDwiArUlVM9bWFnFxHvdz9zewBH55WurrY4ShZWyV+x2dWjjceWG5VpWeI6sA="
+    # create a github personal access token
+    # cd pandas-dev/pandas
+    # travis encrypt 'PANDAS_GH_TOKEN=personal_access_token' -r pandas-dev/pandas
+    - secure: "EkWLZhbrp/mXJOx38CHjs7BnjXafsqHtwxPQrqWy457VDFWhIY1DMnIR/lOWG+a20Qv52sCsFtiZEmMfUjf0pLGXOqurdxbYBGJ7/ikFLk9yV2rDwiArUlVM9bWFnFxHvdz9zewBH55WurrY4ShZWyV+x2dWjjceWG5VpWeI6sA="
 
 git:
     # for cloning