relax base64-bytestring upper bound

[picnoir]

This project is correctly building using base64-bytestring-1.1.0.0.
Relaxing the upper bound accordingly.

$ ghc-pkg list base64-bytestring
/nix/store/wjwacdwx99hmvqzbg9f3zn970iq42gxn-ghc-8.10.4-with-packages/lib/ghc-8.10.4/package.conf.d
    base64-bytestring-1.1.0.0

$ cabal build
Resolving dependencies...
Build profile: -w ghc-8.10.4 -O1
In order, the following will be built (use -v for more details):
 - postgresql-simple-migration-0.1.15.0 (lib) (configuration changed)
 - postgresql-simple-migration-0.1.15.0 (exe:migrate) (configuration changed)
Configuring library for postgresql-simple-migration-0.1.15.0..
Configuring executable 'migrate' for postgresql-simple-migration-0.1.15.0..
Preprocessing library for postgresql-simple-migration-0.1.15.0..
Preprocessing executable 'migrate' for postgresql-simple-migration-0.1.15.0..
Building library for postgresql-simple-migration-0.1.15.0..
Building executable 'migrate' for postgresql-simple-migration-0.1.15.0..

<no location info>: warning: [-Wmissing-home-modules]
    These modules are needed for compilation but not listed in your .cabal file's other-modules: 
        Database.PostgreSQL.Simple.Migration
        Database.PostgreSQL.Simple.Util

<no location info>: warning: [-Wmissing-home-modules]
    These modules are needed for compilation but not listed in your .cabal file's other-modules: 
        Database.PostgreSQL.Simple.Migration

[endgame]

I have built this package using base64-bytestring-1.2.0.1. As a Hackage Trustee, I have published a new revision with base64-bytestring >= 1.0 && < 1.3. Can you update this PR?

Related issue: #37