Install pynvim with --user to avoid permission issues

[skip appveyor]

.travis.yml

@@ -167,6 +167,16 @@ jobs:
         - CMAKE_FLAGS="$CMAKE_FLAGS -DPREFER_LUA=ON"
         - DEPS_CMAKE_FLAGS="$DEPS_CMAKE_FLAGS -DUSE_BUNDLED_LUAJIT=OFF"
         - *common-job-env
+      addons:
+        apt:
+          packages:
+            - *common-apt-packages
+            - python-pip
+            - python3-pip
+            - python-setuptools
+            - python3-setuptools
+            - python-dev
+            - python3-dev
     - name: clang-tsan
       os: linux
       compiler: clang

ci/install.sh

@@ -14,9 +14,9 @@ fi
 
 # Use default CC to avoid compilation problems when installing Python modules.
 echo "Install neovim module for Python 3."
-CC=cc python3 -m pip -q install --upgrade pynvim
+CC=cc python3 -m pip -q install --user --upgrade pynvim
 echo "Install neovim module for Python 2."
-CC=cc python2 -m pip -q install --upgrade pynvim
+CC=cc python2 -m pip -q install --user --upgrade pynvim
 
 echo "Install neovim RubyGem."
 gem install --no-document --version ">= 0.8.0" neovim