Set MATRIX_TOXENV on dynamodb integration builds.

.travis.yml

@@ -34,6 +34,7 @@ matrix:
     env: MATRIX_TOXENV=integration-dynamodb
     stage: integration-test
     before_install:
+      - if [[ -v MATRIX_TOXENV ]]; then export TOXENV=${TRAVIS_PYTHON_VERSION}-${MATRIX_TOXENV}; fi; env
       - ./extra/install_dynamodb.sh
       - ./extra/install_couchbase_client.sh
   - python: '3.4'
@@ -50,6 +51,7 @@ matrix:
     env: MATRIX_TOXENV=integration-dynamodb
     stage: integration-test
     before_install:
+      - if [[ -v MATRIX_TOXENV ]]; then export TOXENV=${TRAVIS_PYTHON_VERSION}-${MATRIX_TOXENV}; fi; env
       - ./extra/install_dynamodb.sh
       - ./extra/install_couchbase_client.sh
   - python: '3.5'
@@ -66,6 +68,7 @@ matrix:
     env: MATRIX_TOXENV=integration-dynamodb
     stage: integration-test
     before_install:
+      - if [[ -v MATRIX_TOXENV ]]; then export TOXENV=${TRAVIS_PYTHON_VERSION}-${MATRIX_TOXENV}; fi; env
       - ./extra/install_dynamodb.sh
       - ./extra/install_couchbase_client.sh
   - python: '3.6'
@@ -82,6 +85,7 @@ matrix:
     env: MATRIX_TOXENV=integration-dynamodb
     stage: integration-test
     before_install:
+      - if [[ -v MATRIX_TOXENV ]]; then export TOXENV=${TRAVIS_PYTHON_VERSION}-${MATRIX_TOXENV}; fi; env
       - ./extra/install_dynamodb.sh
       - ./extra/install_couchbase_client.sh
   - python: '3.6'
@@ -98,8 +102,8 @@ matrix:
     env: TOXENV=pypy-integration-dynamodb PYPY_VERSION="pypy2.7-5.8.0"
     stage: integration-test
     before_install:
-      - ./extra/install_dynamodb.sh
       - if [[ -v MATRIX_TOXENV ]]; then export TOXENV=${TRAVIS_PYTHON_VERSION}-${MATRIX_TOXENV}; fi; env
+      - ./extra/install_dynamodb.sh
       - |
             if [[ "$TOXENV" =~ "pypy" ]]; then
               export PYENV_ROOT="$HOME/.pyenv"