Bug: smspec_node need nums was called incorrectly

Change fortio test to use C++ testarea

Travis fix for Python2.7 and Python3.6 on OSX

Using multibuild (https://github.com/matthew-brett/multibuild) we can skip relying on conda environment.

Clean up the Travis file

Fixed operator< for ecl_nnc_pair_type

The previous implementation returned true even when the compared objects
were equal, and that made std:sort screw up the memory on some cases

Set micro version to 2.3.1

Merge pull request equinor#525 from stefoss23/well_segment_state_ts_t…

…o_cpp

WIP: Well segment collection using std::Vector

Set version to 2.3.0 in code

Merge pull request equinor#510 from joakim-hove/resample-fixupII

The testing of summary_resample is temporarily disabled.

Merge pull request equinor#504 from joakim-hove/summary-restart

WIP: Extend length of case1 in ecl_sum restart testing