Suggesstions w.r.t adhering to haskell PVP

[adithyaov]

trafficstars

Few things to keep in mind/fix as suggested by Jack Kelly, a member of the Haskell trustees:

1. Do not admit version bounds that do not exist, and are allowed to make breaking changes. Basically do not admit major versions that do not exist. For example, the upper bound for base is too leniant as in it admits base versions that can make a breaking change.

2. Put the version bounds only in one place. Remove version bounds on all common dependencies for executables that are dependent on streamly. This includes all the test suits and bench suits. This keeps the dependency bounds information DRY.