Remove node-cache-manager-fs from README.md

[NicolasMahe]

I suggest to remove node-cache-manager-fs from the list of Store Engines of README.md because the lib is not working as expected.

After spending too much time checking my code, I tried another lib and it everything worked as expected.

I found out the lib has already a consequent number of issue related to the problem:

• Data is not cached hotelde/node-cache-manager-fs#23
• get method returning undefined hotelde/node-cache-manager-fs#15
• Breaking change introduced in 1.0.5 hotelde/node-cache-manager-fs#5
• Missing parameter in get method hotelde/node-cache-manager-fs#2

I recommend to use node-cache-manager-fs-hash instead.

[coveralls]

Coverage remained the same at 99.174% when pulling 97d642f on NicolasMahe:patch-1 into 2a5ed3a on BryanDonovan:master.

[coveralls]

Coverage remained the same at 99.174% when pulling 97d642f on NicolasMahe:patch-1 into 2a5ed3a on BryanDonovan:master.

[BryanDonovan]

Thanks!