Add other-modules section to fix warnings

[msakai]

This fixes warnings like the following.

<no location info>: warning: [-Wmissing-home-modules]
    These modules are needed for compilation but not listed in your .cabal file's other-modules: HpcCoverallsCmdLine
                                                                                                 Paths_hpc_coveralls
                                                                                                 Trace.Hpc.Coveralls
                                                                                                 Trace.Hpc.Coveralls.Cabal
                                                                                                 Trace.Hpc.Coveralls.Config
                                                                                                 Trace.Hpc.Coveralls.Curl
                                                                                                 Trace.Hpc.Coveralls.GitInfo
                                                                                                 Trace.Hpc.Coveralls.Lix
                                                                                                 Trace.Hpc.Coveralls.Paths
                                                                                                 Trace.Hpc.Coveralls.Types
                                                                                                 Trace.Hpc.Coveralls.Util

[coveralls]

Coverage remained the same at 36.17% when pulling 670adeecb8ab5e9ec2290000802e5babc4820864 on msakai:feature/fix-missing-home-modules-warning into 04fe42c4533b3244e9fa1c2772aa5e30baf5eef0 on guillaume-nargeot:master.