The ornamental design for a vial with cap, as shown and described.
FIG. 1 is a perspective view showing the new design for a vial with cap.
FIG. 2 is a front view thereof;
FIG. 3 is a back view thereof;
FIG. 4 is a side view thereof;
FIG. 5 is a top view thereof; and,
FIG. 6 is a bottom view thereof.
The evenly dashed broken lines in the drawings illustrate the portions of the design that form no part of the claim. The dot-dot-dash broken line in the FIG. 6 bottom plan view defines the bounds of the claim and forms no part thereof.