Test certificate should be upgraded to >= 2048 bits

[jlaine]

• uvloop version: 0.12.0rc2
• Python version: 3.7
• Platform: Debian/unstable

Running the test suite on Debian/unstable (OpenSSL 1.1.1) fails when loading the test certificate with:

ssl.SSLError: [SSL: EE_KEY_TOO_SMALL] ee key too small (_ssl.c:3816)

I recently encountered the same error with the aioice test suite, the fix is to regenerate a private key + cert of 2048 bits or more.

[jlaine]

Since we seem to use the Python test suite's certificates we can make use of:

python/cpython@e6dac00

[jlaine]

I have submitted PR #218 to update the test certificate / key