Bump minimal version of MATLAB to R2014a

.gitlab-ci.yml

src/@dates/intersect.m

src/@dates/remove_.m

src/@dates/setdiff.m

src/@dates/unique_.m

src/@dseries/dseries.m

src/initialize_dseries_class.m

src/utilities/missing/iscolumn/iscolumn.m

src/utilities/missing/ismatrix/ismatrix.m

src/utilities/missing/isrow/isrow.m

src/utilities/missing/strjoin/strjoin.m

src/utilities/missing/strsplit/private/ischarint.m

src/utilities/missing/strsplit/private/ischarnum.m

src/utilities/missing/strsplit/strsplit.m