Resolve "Fix maven build for Eclipse 2020-06 and Java8"

Closes #58

See merge request ESProjects/SDE!59

update README

Resolve "OSS formatter could be improved for contract refinements"

Closes #57

See merge request ESProjects/SDE!58

Resolve "Add LTL bounded in ocra grammar"

Closes #56

See merge request ESProjects/SDE!57

update profiles for Neon, 2020-06 and 2021-06

add `inf` value to InfiniteLiteral
add PI Literal to grammar
add temporal operators `X~` and `Y~` to grammar

Resolve "Extend OCRA grammar to handle async communication"

Closes #53

See merge request ESProjects/SDE!56

Resolve "Contract name should allow round brackets"

Closes #55

See merge request ESProjects/SDE!55

quotes)

Resolve "Extend OCRA grammar to handle async communication"

Closes #53

See merge request ESProjects/SDE!54

Resolve "Move 'adapter' plugins outside SDE"

Closes #47

See merge request ESProjects/SDE!53

make some test plugin as optional