Fixes
mv: cannot move './static/bootstrap-4.3.1-dist' to './static/bootstrap/bootstrap-4.3.1-dist': Directory not empty
when 'make' is called more than once.
UBHF2ZO23TQWM6SJ4MIHAZG3QMRZ5C6QO5ZHM6LCM7OZP4IAKKSQC
4PSZFZ7Y7SRRFPCVZETWOP7AJYVADC6MNX3RVUP4SRVJJ4TDZDTAC
OEPUOUNBNTHTFZVDXREGBQCKFRCWMVP2MDVK4OA47VK2DBKEWVYAC
FV2M6MOTAP4BJMEKU5XUDVEACWEJGEIRCCE2MRY3F6SF2SFOE3MQC
ZCO73ATUVYUVSVT5SRDXDC27IC2NENL2M6QIFJDI5JFYJFN2OEHQC
rm -rf $(srcdir)/static/bootstrap
rm -rf $(srcdir)/static/fontawesome