The ornamental design for a beveragecoaster, as shown and described.
FIG. 1 is a front perspective view showing my new design of a beverage coaster;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a right side elevational view thereof;
FIG. 5 is a left side elevational view thereof;
FIG. 6 is a top plan view thereof;
FIG. 7 is a bottom plan view thereof; and,
FIG. 8 is another front perspective view showing my new design of a beverage coaster.
The broken lines in FIGS. 1, 2, 4-6, and 8 of the beverage coaster are for the purpose of illustrating environment, and form no part of the claimed design.