Fixes #1037: Adds medium tags to new test files and renames them

[tjmcs]

Fixes #1037

Summary of changes:

• Adds medium tag to the test files identified in Issue Recently added tests need to be labeled appropriately #1037
• Renames those same files as medium tests

Testing done:

• Ran the tests manually, generating coverage tests for each test in each of the test files identified in Issue Recently added tests need to be labeled appropriately #1037

Note: these files were classified as medium tests because the tests they contained (a) tested more than one underlying function and/or (b) made use of the network on the localhost during those same tests; as such, they should be classified as medium (rather than small) tests.

@intelsdi-x/snap-maintainers

[nanliu]

LGTM