.circleci/: Install test-requirements.txt first

test-requirements.txt contains overrides needed to ensure
pip installs suitable versions of dependencies, especially
of pip.

Also move pytest before installing dependencies of coala-ci.

.circleci/config.yml

@@ -15,29 +15,29 @@ jobs:
             echo "export NVM_DIR=$HOME/.nvm" >> $BASH_ENV
             echo "export PATH=~/.local/bin:$PATH" >> $BASH_ENV
 
-      - run:
-          name: install-csslint
-          command: |
-            curl -o- \
-            https://raw.githubusercontent.com/creationix/nvm/v0.33.8/install.sh\
-            | bash
-            [ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh"
-            nvm install 8
-            npm install -g csslint
-
       - run:
           name: dependencies
           command: |
             pip install --user \
+            -r test-requirements.txt \
             -r requirements.txt \
-            -r docs-requirements.txt \
-            -r test-requirements.txt
+            -r docs-requirements.txt
 
       - run:
           name: pytest
           when: always
           command: python -m pytest
 
+      - run:
+          name: install-csslint
+          command: |
+            curl -o- \
+            https://raw.githubusercontent.com/creationix/nvm/v0.33.8/install.sh\
+            | bash
+            [ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh"
+            nvm install 8
+            npm install -g csslint
+
       - run:
           name: install-shellcheck
           command: sudo apt-get install shellcheck