Add checkpoint to validate naming rules of the keys file

[biodavidjm]

Specifically:

• Condition: The conditions names must follow these rules:
  Use only letters (A - Z, both uppercase and lowercase) and numbers (0 - 9). The only special character allowed is underscore (_).
  Very important: A condition name cannot begin with a number (R limitation).

• BioReplicate: biological replicate number. It is based on the condition name. Use as prefix the corresponding Condition name, and add as suffix dash (-) plus the biological replicate number. For example, if condition H1N1_06H has too biological replicates, name them H1N1_06H-1 and H1N1_06H-2