intial commit
updates rvmrc
rename to RTanque
make Heading objects more immutable
move ranges into module
changes max turn range
add max ticks to match
first attempt at radar
adds turret and firing of shells
memoize gui shells; vary shell damage; other small changes
Update README.md
new tick group class; movable class
move Sensors & Command into own files
big refactoring! using movable module; simplifed tick_group; started with some functional tests
simplify gui bot & shell groups; offset shell position to represent turret
refactor tests; clean up movables and radar
adds form to readme
Update Readme
refactor of radar
adds travis config