chore(deps): update dependency sqlalchemy to v1.3.13 (#2778)

* chore(deps): update dependency sqlalchemy to v1.3.13

* Comment out requirement, add explanation for user

* Add explanation of requirements

* specify pg8000 version for py2

Co-authored-by: Leah E. Cole <[email protected]>

Author: renovate-bot

appengine/standard_python37/cloudsql/requirements.txt

@@ -1,5 +1,5 @@
 flask==1.1.1
-psycopg2==2.8.4
-psycopg2-binary==2.8.4
+# psycopg2==2.8.4
+psycopg2-binary==2.8.4 # you will need either the binary or the regular - for more info see http://initd.org/psycopg/docs/install.html
 PyMySQL==0.9.3
-SQLAlchemy==1.3.12
+SQLAlchemy==1.3.13

cloud-sql/mysql/sqlalchemy/requirements.txt

@@ -1,3 +1,3 @@
 Flask==1.1.1
-SQLAlchemy==1.3.12
+SQLAlchemy==1.3.13
 PyMySQL==0.9.3

cloud-sql/postgres/sqlalchemy/requirements.txt

@@ -1,3 +1,4 @@
 Flask==1.1.1
-SQLAlchemy==1.3.12
-pg8000==1.13.2
+SQLAlchemy==1.3.13
+pg8000==1.13.2; python_version > '3.0'
+pg8000==1.12.5; python_version < '3.0'