plot_phased_mag_series: add linewidth & elinewidth
plot_phased_mag_series: add linewidth & elinewidth

Sometimes a phased lightcurve can be easier to read without the
error bars. The default behavior is unchanged.

waqasbhatti/astrobase,lgbouma/astrobase,lgbouma/astrobase,lgbouma/astrobase,waqasbhatti/astrobase,waqasbhatti/astrobase