scikit-hep/scikit-hep: Version 3.4.0

Minor update of dependencies for decaylanguage, histoprint, iminuit and particle. Full set: awkward~=1.4.0 awkward0~=0.15 boost-histogram~=1.1.0 decaylanguage~=0.12.0 hepstats~=0.5.0 hepunits~=2.1.0 hist~=2.4.0 histoprint~=2.2.0 iminuit~=2.8.0 matplotlib>2.0.0 mplhep~=0.3.0 numpy>=1.13.1 particle~=0.16.0 uproot~=4.0.0 uproot3~=3.14.0 uproot3-methods~=0.10.0 vector~=0.8.