fix Travis deployment to gh-pages

Author: Matt Garthwaite

.travis.yml

@@ -12,7 +12,7 @@ env:
     - PROJBUILD=$HOME/projbuild
 
 
-# nci verson is GDALVERSION="3.0.2" and python3.7
+# nci version is GDALVERSION="3.0.2" and python3.7
 jobs:
   include:
     - python: "3.6"
@@ -68,19 +68,20 @@ after_success:
   - codecov
 
 
+before_deploy:
+  - cd docs && make html
+
+
 deploy:
-  script:
-    - pip install numpy==1.16.4
-    - cd docs && make html
   provider: pages
-  skip-cleanup: true
-  keep-history: true
+  skip_cleanup: true
+  keep_history: true
   verbose: true
   on:
     branch: master
     condition: $GDALVERSION="3.0.2" && $TRAVIS_PYTHON_VERSION=3.8.*
-  github-token: $GITHUB_TOKEN2
-  local-dir: docs/_build/html
+  github_token: $GITHUB_TOKEN2
+  local_dir: docs/_build/html
   project_name: PyRate
   email: insar@ga.gov.au
   name: InSAR Team