Run AWS SDK tests on Python 3.7 (#5414)

* Run AWS SDK tests on Python 3.8

* switch to 37

* Update aws-encryption-sdk.sh

* Update dynamodb-encryption-sdk.sh

Author: alex

.travis.yml

@@ -122,9 +122,9 @@ matrix:
         # https://github.com/paramiko/paramiko/pull/1723 is merged
         # - python: 2.7
         #   env: DOWNSTREAM=paramiko
-        - python: 2.7
+        - python: 3.7
           env: DOWNSTREAM=aws-encryption-sdk
-        - python: 2.7
+        - python: 3.7
           # BOTO_CONFIG works around this boto issue on travis:
           # https://github.com/boto/boto/issues/3717
           env: DOWNSTREAM=dynamodb-encryption-sdk BOTO_CONFIG=/dev/null

.travis/downstream.d/aws-encryption-sdk.sh

@@ -6,7 +6,7 @@ case "${1}" in
         cd aws-encryption-sdk-python
         git rev-parse HEAD
         pip install -e .
-        pip install -r test/upstream-requirements-py27.txt
+        pip install -r test/upstream-requirements-py37.txt
         ;;
     run)
         cd aws-encryption-sdk-python

.travis/downstream.d/dynamodb-encryption-sdk.sh

@@ -6,7 +6,7 @@ case "${1}" in
         cd aws-dynamodb-encryption-python
         git rev-parse HEAD
         pip install -e .
-        pip install -r test/upstream-requirements-py27.txt
+        pip install -r test/upstream-requirements-py37.txt
         ;;
     run)
         cd aws-dynamodb-encryption-python